Gemological Testing Laboratory
Quality Assurance maintains a gemological laboratory (gem lab) at the Exchange headquarters in Dallas, Texas. Highly trained gemologists can inspect fine jewelry products for overall merchandise quality, verifying conformance to specified requirements including, but not limited to, stone quality, precious metal weights and contents, workmanship, and merchandise tagging. Adherence to requirements set forth by the Federal Trade Commission, such as trademark and purity stamping is verified as well. Customer-owned merchandise submitted to gem lab for repair, refund, or trade-up is inspected similarly to the new shipment.
In order to ensure top quality merchandise reaches our customers, fine jewelry products procured by the Exchange are inspected before shipment by third party inspection companies at either suppliers’ facilities or the labs of inspection companies. Inspection reports are generated and shared with the Exchange.
Fine jewelry items must be made to meet their specification sheets or the Exchange’s Jewelry Cost Analysis Proposal Worksheet, which are used in inspections by third party inspectors or the Exchange gemologists to ensure that merchandise meets all the specifications agreed upon by the Exchange buyer and the supplier. The Exchange also has specifications for mountings and chains, stamping, and tagging.
Jewelry items will be inspected for quality of diamond(s) and/or stone(s), quality of mounting, precious metal content, stamping and tagging. Diamonds shall be graded for clarity, cut and color based upon the Gemological Institute of America's (GIA's) diamond grading system in conjunction with the Exchange’s specification sheets for the merchandise.
Diamonds shall be graded under 10 power (10x) binocular magnification using Gemological Institute of America's (GIA's) diamond grading system. Color grading shall be accomplished under diffused cool-white fluorescence lighting using a Diamond Colorimeter and a master diamond color grading set certified by the Gemological Institute of America (GIA).
The following jewelry specifications are the minimum acceptable requirements for jewelry to be supplied to The Exchange. All jewelry supplied shall either meet or exceed the following:
Acceptable Carat Weight Ranges
1/8 = .12 to .13
1/7 = .14 to .15
1/6 = .16 to .17
1/5 = .18 to .22
1/4 = .23 to .28
1/3 = .29 to .36
3/8 = .37 to .44
1/2 = .45 to .54
5/8 = .59 to .61
2/3 = .62 to .69
3/4 = .70 to .79
7/8 = .80 to .94
1 ct. = .95 to 1.10
1 1/4 = 1.23 to 1.28
1 1/3 = 1.29 to 1.36
1 1/2 = 1.45 to 1.58
1 3/4 = 1.70 to 1.79
2 cts. = 1.95 to 2.10
2 1/2 = 2.45 to 2.58
3 cts. = 2.95 to 3.10
3 1/2 = 3.45 to 3.54
4 cts. = 3.95 to 4.10
- No extremely thin or thick girdles on the diamond.
- No dark centers in the diamond which are the result of light leakage caused by too deep of a pavilion.
- Round diamonds must have a table percentage between 52% and 67%.
- Round diamonds must have crown angles no less than 30 degrees or greater than 38 degrees.
- Diamonds must have good or better symmetry and polish grade rating per Gemological Institute of America's (GIA's) diamond grading system.
- No chips, breaks or large "opens" in the stone. Diamonds must be whole and complete.
- No laser drilled diamonds.
- No treated (clarity enhanced) diamonds including fracture filled treatment.
- No diamonds with very strong fluorescence under ultra-violet light.
- Culet size on diamond must be None - Medium.
- On all items containing more than one diamond, the diamonds shall face up approximately the same size and color.
- Diamonds must be properly seated, securely set and not loose.
- Round diamonds must be well cut and proportioned.
- Fancy cut diamonds must be well cut and proportioned. Unattractive or unbalanced cuts will not be acceptable.
- All single cut diamonds must have 17 facets or more. Full cut diamonds must have 58 facets or more.
- Color enhanced or treated diamonds are only acceptable when specified and described.
Mountings, Stamping and Tagging
The requirements for mountings, stamping and tagging are outlined in the following Appendices:
- Appendix I - Specifications for Precious Metal: Mountings
- Appendix II - Requirements for Stamping
- Appendix III - Specifications for Tagging
- Colored stones shall be graded for clarity, cut and color per the specification sheet.
- All colored stones shall be of natural origin unless specified in the contract as being synthetic, simulated or imitation. All treatments must be disclosed on the specification sheet.
- Colored stones shall not have any eye-visible damage when viewing ‘face-up’.
- No colored stones which are enhanced by a non-permanent or superficial process shall be accepted unless it has been agreed upon by the Exchange buyer, and stated on the specification sheet and hang tag.
- Oiling of emeralds is acceptable as it is industry practice. Excessively oiled and secreting emeralds are not permitted.
- Color, quality, and size of colored stones shall be equal to or better than what has been specified on the specification sheet.
- In any jewelry item containing more than one of the same-colored stone, all stones shall be matching in color and size unless the design of the piece of jewelry is purposely made for variation.
- Colored stones shall be graded under 10 power (10x) binocular magnification or greater to determine authenticity of stones, enhancements and to determine durability problems.
- Colored stones shall be inspected under diffused cool-white, fluorescent light.
- Jewelry merchandise purchased by the Exchange is subject to random sampling inspections. Any deficiency in diamond and colored stone quality and/or mountings shall be considered quality defects and any deficiency in stamping and/or tagging shall be considered non-conformance. A shipment can fail for either quality and/or non-conformance.
- Selected samples will be inspected in their entirety, i.e., quality of diamond(s) and/or stone(s), quality of mounting, precious metal content, stamping and tagging. All inspections shall be accomplished using a 10x (power) binocular magnification to identify natural gemstones and to assure compliance with the Federal Trade Commission's (FTC) Guidelines for the Jewelry Industry and to identify manufacturing defects.
- Commonly found jewelry defects are listed in the Appendix IV - Glossary: Explanation of Defects.
Appendix I: Specifications for Precious Metal
- All shipments are subject to inspections performed in the following manner:
- All items will be inspected under cool-white, fluorescent lighting with the unaided eye and ten-power (10x) binocular.
- Working mechanisms such as clasps will be opened and closed to assure smooth, unrestricted function.
- Selected samples will be weighed to assure merchandise will meet or exceed the contracted weight.
- Inspection of the purity and trademark will be accomplished with the aid of ten-power (10x) magnification to assure legibility.
- Tagging will be inspected for adherence to tagging requirements.
- Copies of assay tests for gold content will be submitted by suppliers to QA gem lab upon request. QA may conduct random gold assays to assure compliance to laws regulating karat fineness.
Minimum Requirements for Precious Metal Merchandise
- All gold items will be plumb gold as defined by the Federal Trade Commission's Guidelines for the Jewelry. Precious Metals and Pewter Industries, 16 C.F.R. Part 23, reference section 23.4, the National Stamping Act and the National Gold & Silver Stamping Act 15 U.S.C. 291, et. seq. and the FTC.
- All merchandise must comply with FTC regulations and laws governing the production of fine jewelry, precious metals, diamonds, and gemstones.
- All rings for stock will be furnished in size seven (7) for ladies and size ten (10) for men unless specified on individual order. All finger sizes must be within 1/4 size of the required size. Other ring sizes are available through special order process.
- Earring backs and posts will be of sufficient strength to withstand normal wear without bending or becoming loose. The weight of the earring backs will be equal to or heavier than 0.20 grams. Earring posts should be 7/16" long with a minimum thickness of 1 mm.
- Castings will be complete and show no signs of eye-visible damage.
- Settings must be sufficient to hold the diamonds/colored stones securely. Loose diamonds /colored stones are not acceptable.
- Items will be free of porosity and metal fractures of cracks resulting in the loss of structural durability within the mounting. Magnification will be used to confirm defects.
- Items will be uniform in thickness, color, and polish, properly constructed, strong and durable for normal wear. Indentations, holes, excessive, insufficient, or discolored solder is not acceptable. Proper construction and strength of solder joints will be determined when necessary under magnification.
- Items will be smooth and uniformly polished, free of file marks, scratches, nicks, protrusions, rough edges, tarnish, or ridges visible to the unaided eye.
- Clasps will be of sufficient weight, strength, and size to support the item.
- Items supplied will meet or exceed the required weight specified in the contract.
- All prongs or heads will be uniform, straight, and flush with the diamond/colored stone. The prongs will not have sharp edges or points. Excessive prongs and flashing, which detracts from the appearance of the item, will not be accepted. Insufficient prong coverage or over polished prongs, which affect the durability of the prong or security of the stone, is not acceptable. Diamond/colored stone pavilions will not protrude into the finger area.
- All white gold items will be rhodium plated to a bright white finish.
- All items must be furnished in the length, width and thickness as specified on their specification sheets.
- Jump rings must be soldered. No excessive amounts of solder that will affect appearance and/or product.
Appendix II: Requirements for Stamping
All jewelry items will be stamped with the following information per the requirements established by the National Gold & Silver Stamping Act 15 U.S.C., sections 291 through 300 and the Federal Trades Commission's Guides for the Jewelry, Precious Metals and Pewter Industries 16 C.F.R. Part 23.
- Platinum will be stamped Platinum / PLAT / PT950 / PT900.
- Karat gold purity will be stamped with one of the following:
10 karat gold 10k or 10kt 417 14 karat gold 14k or 14kt 585 18 karat gold 18k or 18kt 750 Baht gold 23k or 23kt 96.5 Sterling Silver SS 925
Stamping of the trademark will be placed as closely to the purity mark as possible and will be approximately equal in size. Locations of stamping are as follows:
- Rings: Stamping placement inside shoulder of the shank as to not affect the resizing capabilities.
- Earrings: Each earring post requires both the purity and trademark of the supplier. It is sufficient for the back of the earring to be stamped with the correct purity and supplier trademark.
- Pendants: The placement of the purity and trademark must be on the back of the bail or on the rear of the mounting.
- Chains: The supplier's trademark and purity mark can be stamped on the clasp tongue, jump ring or metal plate connecting the clasp.
- Bracelets: Bracelets are to be stamped on the clasp junction, tongue, or safety latch.
All merchandise will be stamped inside the shank using the following examples:
- If the item has a center diamond, the minimal acceptable weight of that stone will be stamped. For example, a 1/4 carat should be stamped 0.23ct. If a contract range is established for a minimum, then the minimum range should be used. For example, 0.23-0.27 carat is acceptable, then 0.23ct should be stamped.
- If the exact weight of the main diamond is known, and it exceeds the minimum, that weight should be stamped.
- If there is no main diamond, and the item is a one carat total weight, 1.00 CTW. Should be stamped. If a range is established by the contracting officer, the minimum required weight should be stamped. For example, an item with 20 diamonds with a range of 0.95-1.10CTW. should then be stamped 20/.95CTW.
Appendix III: Specifications for Tagging
All merchandise must be pre-ticketed with one gray photocomposed barcode label for items that retail for $999.00 and less and a white barcode label for items that retail for $1000.00 and greater. This barcode shall be obtained from:
A Division of FineLine Technologies
Contact: Renee Zermeno
Photocomposed barcode specifications are as follows:
- Size 2.5" x 0.45" barbell
- Color - gray or white
- Format - 40 labels per sheet
- Reduction - 52%
The supplier shall provide the following information to Data 2, Inc.:
- UPC Code - 12 digits
- AAFES CRC # - 7 digits
- Item Description; up to 26 digits
- Example 1: Princess cut diamond solitaire
- Example 2: Emerald / diamond pendant
- Number and minimum total weight of diamonds and / or colored stone description; up to 17 digits
- Example 1: 1/.25ct and 25/.75ctw.
This item contains one (1) 0.25-carat center diamond and twenty-five (25) diamonds with a total weight of 0.75 carats. The total weight of the item is 1.00 ctw.
- Example 2: 25/.25ctw.
This item contains twenty-five (25) diamonds with a total weight of 0.25 ctw. Synthetic, simulated or imitation gemstones shall be identified as such. An example would be: "SYNTHETIC EMERALD" which would be stated on the tag under item description.
- Example 1: 1/.25ct and 25/.75ctw.
- Minimum clarity and color of diamonds in GIA grading terms; up to eight (8) digits
- Example 1: SI2/G
- Karat and color of gold; up to thirteen (13) digits
- Example 1: 14kt. YG
- Example 2: 10kt. WG
- Minimum gram weight (GR) of the item; up to twelve (12) digits.
- Example 2: 2.5 grams
- AAFES or supplier style number up to twenty (20) digits. AAFES determines which style number is applied to the tag.
- Country of origin; up to five (5) digits
- Supplier's name; up to twenty (20) digits
- AAFES sell price supplied on the purchase order; up to nine (9) digits
The supplier shall pay the cost of tagging to Data 2, Inc.
Appendix IV: Jewelry Defects Glossary
Master Sample: A master sample is an item that is inspected against buyer specifications for diamond / stone quality, color, size, shape, gold weight, stone setting and basic manufacturing quality, and found acceptable. A master sample of an item is kept in QA as the minimum acceptable reference standard for future shipments of that item, thus the term master sample.
Below Clarity Of The Master Sample: The master sample sets the minimum acceptable standard for the item. If the diamond / stone clarity does not meet or exceed the quality of the master sample, the item is considered below the contract specifications, below clarity and not acceptable to The Exchange.
Note: The GIA Diamond Clarity Scale is used to determine the diamond quality.
Below Color Of Master Sample: The master sample sets the minimum acceptable standard per item. If the diamond / stone does not meet or exceed the color of the master sample, the item is considered below the contract specifications and below the acceptable diamond / stone color.
Note: The color of diamonds is determined by comparing the stone to a certified GIA Diamond Color Master Sample Set and the use of a Diamond Colorimeter.
Below Weight: Each jewelry item has a contracted karat weight for the metal to assure consistency of the item no matter what karatage. (10kt, 14kt, 18kt, etc.) By Contract, The Exchange requires that the item meet or exceed the required weight.
Bent Post: Usually this is used in reference to earring posts, although it can be used for other items of jewelry that make use of posts (pegs) to attach gemstones to the mounting. Bent posts are usually the result of extremely thin posts being used which are not durable and can not withstand normal wear. Reference each specific The Exchange specification to determine which post thickness to use.
Bent Prongs: The prong is the narrow metal support, usually used in groups of four, six, and eight, to hold a gemstone in the mounting. If the prongs are not uniform around the outside of the gemstone, then they are considered bent which causes a durability problem and weakens the security of the setting. This can be a result of poor setting or from impact during a different manufacturing phase.
Broken Links: This refers to a break in a chain or bracelet which is usually
the result of poor crystallization or
Broken Prongs: The prong is broken, usually at the seat or lower, and can be attributed to either poor crystallization or over-cut prongs.
Burnt Facets: This is surface clouding of gemstones, usually diamonds, which is caused by excessive heat generated during the polishing process.
Cavity On Crown: Cavity refers to any opening or indentation on the surface of a polished gemstone. A cavity shall be called when the location is on the crown and is easily visible at 10X magnification or seen with the unaided eye.
Chipped Diamonds / stones: A chip is a shallow break on a gemstone, which is potentially a durability problem to the future integrity of the stone.
Clasp Not Holding: Clasps are any device meant to join and hold two parts of a necklace, bracelet, or anklet.
If the clasp does not close and hold securely, it does not perform the function it was designed for and is considered a defect.
Cracked Mountings: The mounting is considered the metal part of the piece of jewelry. It can be a ring, bracelet, necklace, pin, etc.
The mounting has cracks due to the manufacturing of the item, whether cast or fabricated. These cracks can be actual splits in the metal structure or a series of fine porosity having the appearance of a split in the metal. This affects the durability and life expectancy of an item since the damage is a result of damage to the metal's crystal structure or the bonding of the different alloys together leaving the metal weak and possibly resulting in further damage.
Cracked Prongs: An actual split in the prong, which results in a durability problem. The problem can be a result of improper setting, either over-cutting of a prong, as a result of excessive force in bending the prong resulting in stress damage or fine cracks, or from the metal casting, which could be a result of poor crystallization.
Dangerous Knot: A knot is defined as an included crystal, which reaches the surface of the diamond.
Dangerous Feather: A feather is defined as any break that reaches the surface of the stone / diamond.
A dangerous feather is one that could affect the clarity of the stone by extending further causing other durability problems.
Defective Clasp: This pertains to any problem with the clasp other than that the clasp will not hold shut. Examples would be: Clasp will not open; clasp tongue does not fit properly into the box, insufficient solder connecting the clasp to the jewelry, etc.
Diamonds Below Clarity: All The Exchange merchandise is purchased under contract specifications, which determines the minimal acceptable diamond clarity. Any item submitted to The Exchange must meet the minimum clarity specifications.
Diamonds Out Of Round: Symmetry plays an important factor in the grading of a gemstone as it does in the The Exchange specifications. Any round or brilliant cut diamond that does not have a truly circular girdle outline is considered out of round.
Excessive Glue: Epoxy glues are sometimes used to assist in the setting and securing of a gemstone or pearl into a mounting. The glue should be restricted to the immediate area of the stone or pearl that comes into contact with the mounting. Glue visible on metal or the gemstone or pearl face-up is unacceptable.
Excessive Metal Flashing: Any metal that is not inherent to the design of a piece is considered as excess metal and is usually the result of faulty or insufficient clean-up prior to or after casting. Examples of this would be: little spheres or nodules attached to the mounting caused by poor vulcanization resulting in the attachment of air bubbles to the wax mold prior to burn out or excessive metal flashing caused by wax mold deterioration / leakage and improper wax clean-up prior to investing the wax mold.
Excessive Tall Prongs: The prongs should never exceed 75% of the height of the stone / diamond and not cover more than 50% of the crown angle. Excessive prongs are those prongs, which are higher than the surface of the stone / diamond face-up. The main problems are that the prongs no longer protect the stone / diamond but actually are a detriment since they catch and snag tending to bend easier and often times resulting in loss.
Extremely Thick Girdle: An extremely thick girdle is very distracting under 10X magnification as well as to the unaided eye. The extra thickness simply adds unnecessary weight to the finished stone / diamond and can cause setting problems and security issues.
File Marks / tool Marks: These terms are interchangeable, the first being a bit more specific as to the cause of the defect. These refer to any markings on the surface of the metal, which were not intended per the design, e.g., scratches, nicks, gouges, etc.
Flimsy Earring Backs: Earring backs must be sufficient for NORMAL use. Earring backs that are too small to hold in your fingers or too thin to bend while trying to place onto the post are not acceptable for normal use.
Glue Failure: Pearls are usually attached to a post on a mounting by applying epoxy cement / glue inside the drill hole of the pearl and attaching to the post. This epoxy cement / glue is formulated by mixing equal amounts of resin and catalyst. Often times the glue loses its bond, whether improperly mixed or having come into contact with a destructive agent, which is noted as glue failure.
Incomplete Casting: This refers to any void, crack, or opening in a finished metal mounting usually a result of the casting process.
Insufficient Prong Coverage / Insufficient Setting: Prongs are used to secure the stone/diamond into the mounting. When improperly set, the stone/ diamond is in danger of coming loose from the mounting and possibly resulting in the loss. When this occurs, we refer to the problem as insufficient prong coverage.
Insufficient Solder: The area that has been soldered has gaps in the solder flow weakening the solder area / joint.
Knife Edge Girdles: Defined simply as extremely thin girdle; such a girdle is highly susceptible to future damage. This condition presents a possible and very probable durability problem to the future integrity of the diamond.
Large Extra Facet: An extra facet is defined as any facet in excess of those normally required to complete the faceting pattern of the given cutting style.
If there is a large extra facet that detracts from the face-up appearance, at 10X magnification or with the unaided eye, and the symmetry of the diamonds cut, it shall be rejected per The Exchange specifications. If the extra facet is not easily visible face-up or is contained to the girdle area, it could be acceptable.
Large Natural: The definition of a natural is a portion of the original surface or skin, or a rough diamond which is sometimes left on a fashioned stone, usually on the girdle, to indicate the maximum yield has been obtained. As with a large extra facet, an extremely large natural detracts from the face-up appearance as well as the symmetry of the diamond.
Laser Drillholes: Holes in a diamond's surface produced by a laser. This is an enhancement process used to improve the appearance of a diamond, which contains dark inclusions. The Exchange does not accept or purchase products with this type of treatment.
Loose Stones / diamonds: Merchandise that has been received with insufficient setting of the gemstones resulting in the stones / diamonds moving or spinning in the setting. The stones / diamonds are not secured properly allowing the stones / diamonds to spin causing the prongs to wear quicker than normal and increasing the possibility of loosening the stones / diamonds in the mounting.
Marred Special Finish / Poor Special Finish: Marred defined means to injure or damage so as to make imperfect, less attractive, etc.
A special finish is any form of metal treatment that is applied to a mounting other than a polished surface, e.g., matte or sandblasted finish, satin finish directional or non-directional, butler finish, etc.
Mismatched Color: When a piece of jewelry has more than one stone / diamond in the mounting, it is required by The Exchange that they matched in color. This means that all similar colored stones or diamonds in any one item of jewelry should face-up approximately the same color. An example of this would be a diamond cocktail ring with five stones: all diamonds should be approximately the same color. It would not be acceptable for a diamond to be "H" color and the other four diamonds to be an "L" color. The transition in color is too obvious.
Missing Prongs: Stone mountings consist of heads usually with four or six prongs for each stone to be set. If the item has four prongs, then all four prongs should be intact and securing the stone. If one or more prongs are missing, it becomes a durability problem, which is unacceptable.
Missing Stones / Diamonds: Quite obviously, the mounting was received without a stone / diamond.
Nicks On Stones / Diamonds: These are obvious eye-visible abrasions or small chips that detract from the appearance and / or beauty of the stone / diamond. An example would be a huge unpolished or abraded white area on the crown of a polished and faceted deep red ruby.
Nicks On Mounting: Any small cuts, indentations or chips on the surface of a mounting.
Overcut Prongs: All prongs have seats cut into the prongs to enable stone / diamond placement. The standard for cutting of a seat is the removal of one-third to one-half the prong thickness. The removal of more prong metal than this weakens the prong's durability and the security of the stone / diamond.
Poor Crystallization: This is the result porosity has on the composition of the metal structure during casting. The causes are numerous and can have unlimited combinations from the deviation of routine casting procedures.
There are two different types of porosity: surface porosity and internal porosity.
Some of the causes could be: faulty spruing, incomplete burnout, air pressure from torch flame, lack of or insufficient flux, excess of old metal, overheating of metal, insufficient metal, trapped gases or improper cooling.
Poor Polish: Polishing is a cutting action where metal is removed using an abrasive compound. Buffing is a combination of a cutting and burnishing action where some metal is removed, although most is burnished to a high, bright finish. This effect produces the glitter and shine that first attracts attention. If steps are deleted or forgotten, the results shall be immediately noticeable as uneven, rough, flat, or scaly areas, which would be detrimental to the sale of the item.
Poor Rhodium Plating: Rhodium plating is the standard practice of plating white metal, gold or silver, with rhodium to make a thin, hard bright white, highly reflective, and oxidation-resistant surface.
There are two common examples of poor rhodium plating:
- Spotted rhodium: usually eye-visible, is caused by the burning
of the plating solution
or contamination during the plating process
- Matted white rhodium: always eye-visible, is the result of poor
metal surface preparation
during the polishing phase of production.
Poor Sizing: Finger sizes vary which requires that a method of reducing or enlarging a ring be developed. This method is referred to as sizing a ring. The process is the removal of metal to make an item smaller and the addition of metal to increase the size. In order to accomplish this, the item is cut and then soldered back together with an alloyed solder. There are established procedures for this process, which, if followed, prevent most problems that are referred to as poor sizing. Poor sizing can be many different things: heavy porosity in the sizing seams, uneven misshapen shank, thin shank, insufficient solder at sizing seam, file marks, poor polish, etc.
Poor Special Finish / marred Special Finish: See Marred Special Finish
Porosity: Porosity is the unsoundness in cast metals caused by the presence of small pores, holes or voids in the metal. Also see Poor Crystallization.
Post Thread Damage: Earring posts are often threaded for securing the earring to the back. To achieve this, the metal is threaded using a circular stock or round die holder for making external threads and hand taps are used to make the internal threads in the earring back. As with any thread, the threads can be stripped or damaged easily, especially since jewelry metals are significantly softer than other metals.
Shank Out Of Round: The shank of a ring should be round and symmetrical. Occasionally, the shank is distorted and uneven, which is considered out of round.
Sharp Prongs: Prongs that have not been finished (burred) properly leaving the top or claw sharp. This results in snagging of articles of clothing and possible cuts or scratches to skin.
Shopwear: When an item of jewelry is manufactured and placed into stock bins waiting for an order to be placed, the item may show signs of slight wear from rubbing, tarnishing or a dullness called shop wear.
Stones / diamonds Out Of Mounting: Items received for inspection, in which the stones / diamonds have not been secured properly in the setting; stones are separate from the finished piece of jewelry.
Stones / Diamonds Overlapping: This problem is found most prevalently in channel-set and pave-set merchandise. When the setter is placing and securing the stones / diamonds into the mounting, each should be set into the channel mounting without touching or overlapping the other.
Stones / Diamonds Set Crooked: Seats are cut into prongs to assist in securing the stone / diamond in the mounting. Careful precision is necessary to assure that when burring out the seats, that each seat is cut at the same prong depth or the result shall be a tilted or crooked stone / diamond in the head, which is extremely visible to the unaided eye.
Table Exceeds 67%: The Exchange specifications state an acceptable range allowable for the table percentages to maintain good symmetry in cutting proportions of diamonds. This range is 52% through 67%.
Table Off Center: The edge of the table on the left side of the diamond is noticeably closer to the girdle than the table edge on the right. Some diamonds have tables so off center that the reference line bows in on one side and out on the other. The reference line refers to the top bezel facet in the right, the top of the star facet, and the connecting bezel facet top left side.
Table Not Parallel: This occurs when the table is not parallel to the girdle or when the girdle is obviously wavy under either 10X magnification or the unaided eye.
Tarnished Mounting: Tarnishing is the term given to the undesirable dulling, discoloring, luster destroying film that forms on a metal surface during its exposure to atmospheric conditions. Tarnishing develops for other reasons as well. The relative purity of the metal has its effect. Alloyed metal with greater alloy metal content such as copper, tarnish more rapidly and easily in proportion to their alloy metal content. Rough surfaces tarnish more quickly than smooth ones as well as contact with sulfur even in minute concentrations such as storage in cardboard boxes containing sulfur compounds.
Tarnished Solder: See above explanation of tarnishing: usually seen on a piece of jewelry within a seamed area where a lower graded solder was used.
Thin Prongs: A prong is a tapering, pointed, projecting spur that rises from a setting and is bent over a stone to hold it in place. The prong is a very delicate extension of the mounting easily damaged by over-cutting of the stone seat, over-filing or over-polishing. If any of these situations occur, the prong becomes weak and shall not hold the stone securely as its purpose was designed.
Thin Shank: The shank is the area of a ring wrapping around the sides and bottom of the finger. A shank can be over-filed, over-polished or cast thin, which can be a serious detriment to the wear life of a ring.
Twisted Links: This refers to chains. All links should be evenly attached and the chain should lay flat.
Uneven Surface: When an article of jewelry has been finished properly, the metal flows smoothly and evenly. If finishing has been done incorrectly, the surface is uneven and wavy, causing distortion of the item.