Authenticity Guarantee for Jewelry
Tolerance Ranges for Jewelry Authenticity Guarantee
Authenticity Guarantee for jewelry is limited to a review of claims regarding item quality and characteristics listed by the seller. These claims are assessed within defined ranges and tolerances. Below is a detailed overview of those defined ranges and tolerances.
Clarity is evaluated based on the area of the stone that is visible. Areas of the stone that are covered by the setting will not be part of the evaluation. Stones listed as VVSI, VVS2, VS1, VS2, SI1, SI2, I1, I2, I3 will be verified with a - 1 tolerance.
Clarity grade for Flawless or Internally Flawless stones will not be confirmed. Stones having a carat weight of less than 0.15ct will also not be verified for diamond clarity.
For colorless diamonds, jewelry experts will verify the listed color value and accept a –2 tolerance from the lowest value indicated. For example, if a listing states the color is G and the expert determines the color is likely I, the diamond will pass color verification. Similarly, if the listing states the color is J-K and is likely L-M, the diamond will pass color verification.
Please note, D-Z diamonds with a weight below 0.25ct will not be verified for color.
For fancy-colored diamonds, experts will only confirm non-trade term hues. For example, if a listing states that a diamond is “fancy yellow”, experts will confirm that the hue is yellow, but they will not confirm the saturation level. If the listing states that a diamond is “Canary yellow”, experts will confirm that the hue is yellow, but will disregard the term “Canary”.
Colored stones color
If a gemological or trade term is used in the listing and the color appears to be close to term definition, it is acceptable. If a non-gemological term is used in the listing, verification will confirm the term used represents the color of the actual item.
A gemological or trade term describes specific colors and qualities of gemstones that are typically assigned to gemstones of superior quality and rarity. Common trade terms for colored gemstones include Pigeon Blood Red, Royal Blue and Padparadscha Sapphire. These terms must fulfill the Gübelin Gem Lab criteria for proper use which requires the gemstone accurately represent the trade term and its corresponding Gübelin Gem Lab definition.
Stones weighing 0.40 ct or more per stone have an acceptable tolerance of -10%. Stones that weigh less than 0.40 ct have an aggregate tolerance of -25%.
Assembled stones are stones constructed out of two or more materials and are not eligible for Jewelry Authenticity Guarantee.
Common assembled stone types include:
- Doublet: A doublet consists of two joined segments
- Triplet: A triplet has three segments, or two segments separated by a layer of colored cement
An expert will verify that the size of the item matches the size listed by the seller (i.e., inches, millimeters, standard ring sizes, etc.). Necklaces, bracelets and bangles will have a tolerance of +/- ¼ inch. Rings will have a tolerance of +/- 1 full ring size. For long necklaces, 24 inches or longer, a tolerance of up to +/- ½ inch will be accepted.
Please note, resizing an item may result in metal purity and/or composition variances in the area that was modified for resizing purposes (i.e., metal alloys used to modify size may affect metal purity in sections modified).
Gemstones that are eligible for Authenticity Guarantee are commonly treated. Below is a list of the most common gemstone treatments that are acceptable for verification. This list does not represent all possible treatments that could apply.
- Ruby: Heating, healing of fractures (residues), clarity enhancement, glass filling, dyeing
- Sapphire: Heating, clarity enhancements, titanium diffusion, beryllium diffusion, dyeing
- Emerald: Clarity enhancement, dyeing
- Tourmaline: Heating, clarity enhancement, irradiation (red or pink)
- Topaz: Heating (pink), irradiation (blue, brown), coating
- Tanzanite: Heating, clarity enhancement
- Peridot: None
- Garnet: Heating (demantoid)
- Aquamarine: Heating
- Cat’s eye chrysoberyl: None
- Alexandrite: Clarity enhancement
- Spinel: Heating
- Morganite: Irradiation
- Moissanite: None
- Cryptocrystalline Quartz: None
- Shell: None
Please note, clarity enhancements can be performed on any stone that has a fracture but is more common in some gemstones than others.
Treatments that cannot be verified
- Heating: Aquamarine, demantoid garnet, topaz (pink), tourmaline (blue to green), tanzanite. Low temperature in ruby and sapphire is sometimes detectable but not under Authenticity Guarantee.
- Irradiation: Cannot be proven in any colored stone. Some blue topaz is assumed to be treated because of its depth of color.
- Beryllium diffusion: Can be detected but only with sophisticated chemical analysis.
Additionally, claims that colored stones from this list are untreated will not be verified.
Gemstone treatment definitions
- Heating: Heating a stone at temperatures that may vary from 300C to 1800C (depending on the stone) to change the color or improve clarity.
- Healing of fractures: Causing fractures to grow back together during heat treatment using a flux. This is almost exclusively done to rubies and is called ‘residues’ in the gemstone trade because of the whitish flux that is left behind.
- Clarity enhancement (fracture filling): Filling fractures that are open to the surface with substances such as oils, resins or glass to make them less visible. In most cases this is not a permanent treatment.
- Glass filling: Usually refers to rubies filled with lead glass, although it can apply to silica glass. Lead glass filling is mostly used on very low-quality ruby that could not be cut into a stone if it were not held together by the glass.
- Titanium diffusion: Using high temperature heat treatment to cause titanium to enter the surface of a sapphire, creating a blue color in a surface layer.
- Beryllium diffusion: Using high temperature heat treatment to cause beryllium to enter the surface of a ruby or sapphire to change the color, depending on the starting material. This treatment can be in a surface layer or extend throughout the stone. It is not common for rubies.
- Irradiation: Exposing a stone to ionizing radiation such as fast electrons or gamma rays to change its color.
- Coating: Applying a foreign material to the outside of a gemstone to change its color. This treatment is usually not permanent.
- Dyeing: Filling fractures or openings at the surface of a stone with a foreign colored material to create an artificial color.
In some cases, if it’s not possible to determine whether an item is unstable, laboratory-grown or has been treated using then-current techniques and technology, treatment status of the item is undetermined and will pass verification.
If an item has numerous stones that weigh less than 0.20 ct., the precise number of stones in the item will not be verified.
Metal gram weight
If listed, the total gram weight of the metal-only items will be verified. Metal weights will not be verified on finished jewelry items containing other non-metal materials (i.e., stones, enamel, etc.).
For metal only items:
- If the gram weight is 5% below stated weight, it will pass verification.
- If the gram weight is 5-10% below stated weight, it will require buyer approval. If a buyer rejects, the item will be returned to the seller.
- If the gram weight is 10% or more below the stated weight, the item will be returned to the seller.
The following metals and metal purities are eligible for verification.
Please note, resizing an item may result in undisclosed composition variances (i.e., metal alloys used to modify size may affect metal purity).
Silver purity conversion chart
Silver must be at least 92.5%+ Ster., Solid Silver or Sterling Silver
Purity less than 92.5% silver cannot be marked as Ster., Solid Silver and/or Sterling Silver unless the item is a coin or coin silver having a minimum purity of 90% or more.
Tolerance: 1% or 10 parts per thousand. For example, if listing states 925 fineness, eBay will pass a testing result of 915 fineness but will fail a testing result of 914 fineness.
The term "silver" can be used to describe a product or part composed throughout of an alloy containing less than 900 parts per thousand, if the term is accompanied by an equally conspicuous, accurate designation of the item’s silver content.
|Common name||Parts of silver||% of silver purity||Fineness|
|Fine or Pure Silver||999.9/100||99.90%||999|
Based on FTC guidelines, a jewelry item can be stamped “Gold” without a corresponding numerical value of “parts of gold” only if purity is 99.9%.
Gold purity conversion chart
GOLD = k, Kt, Karat, K Gold, Kt Gold, Karat Gold, Gold (if 99.9%+ purity)
Tolerance: ½ a karat or 0.5/24 parts of gold or 0.021 % of gold purity. For example, if listing states 14 parts of gold, eBay will pass a testing result of 13.5 parts of gold but will fail a testing result of 13.49 parts of gold.
Please note, purity range below 9K will not be verified
|Number of karats||Parts of gold||% of gold purity||Fineness|
|9k, 9Kt, 9 Karat, 9K Gold, 9Kt Gold, 9 Karat Gold||9/24||37.5||375|
|10k, 10Kt, 10 Karat, 10K Gold, 10Kt Gold, 10 Karat Gold||10/24||41.7||416/417|
|11k, 11Kt, 11 Karat, 11K Gold, 11Kt Gold, 11 Karat Gold||11/24||45.8||458|
|12k, 12Kt, 12 Karat, 12K Gold, 12Kt Gold, 12 Karat Gold||12/24||50||500|
|13k, 13Kt, 13 Karat, 13K Gold, 13Kt Gold, 13 Karat Gold||13/24||54.1||541|
|14k, 14Kt, 14 Karat, 14K Gold, 14Kt Gold, 14 Karat Gold||14/24||58.3||583/585|
|15k, 15Kt, 15 Karat, 15K Gold, 15Kt Gold, 15 Karat Gold||15/24||62.5||625|
|16k, 16Kt, 16 Karat, 16K Gold, 16Kt Gold, 16 Karat Gold||16/24||66.6||666|
|17k, 17Kt, 17 Karat, 17K Gold, 17Kt Gold, 17 Karat Gold||17/24||70.8||708|
|18k, 18Kt, 18 Karat, 18K Gold, 18Kt Gold, 18 Karat Gold||18/24||75||750|
|19k, 19Kt, 19 Karat, 19K Gold, 19Kt Gold, 19 Karat Gold||19/24||79.1||791|
|20k, 20Kt, 20 Karat, 20K Gold, 20Kt Gold, 20 Karat Gold||20/24||83.3||833|
|21k, 21Kt, 21 Karat, 21K Gold, 21Kt Gold, 21 Karat Gold||21/24||87.5||875|
|22k, 22Kt, 22 Karat, 22K Gold, 22Kt Gold, 22 Karat Gold||22/24||91.7||916/917|
|23k, 23Kt, 23 Karat, 23K Gold, 23Kt Gold, 23 Karat Gold||23/24||95.8||958|
|24k, 24Kt, 24 Karat, 24K Gold, 24Kt Gold, 24 Karat Gold, Gold||24/24||99.9||999|
Platinum purity conversion chart
PLATINUM = Pt., Plat or Platinum if preceded by a number indicating parts per thousand of pure Platinum (95%+ purity does not require a number preceding mark)
Tolerance: 1% or 10 parts per thousand. For example, if the listing states 950 fineness, eBay will pass a testing result of 940 fineness but will fail a testing result of 939 fineness.
Please note, platinum may include undisclosed palladium.
|Metal mark||Parts of platinum||% of platinum purity||Fineness|
|850Pt., 850Plat., 850 Platinum||850/1000||85%||850|
|900Pt., 900Plat., 900 Platinum||900/1000||90%||900|
|950Pt., 950Plat., Platinum||950/1000||95%||950|
|999Pt., 999Plat., Platinum||999.9/1000||99.9%||999|
Palladium purity conversion chart
PALLADIUM = Pall., Pd. or Palladium if preceded by a number indicating parts per thousand of pure Platinum Tolerance: 1% or 10 parts per thousand. For example, if the listing states 950 fineness, eBay will pass a testing result of 940 fineness but will fail a testing result of 939 fineness.
|Marking||Parts of palladium||% of palladium purity||Fineness|