Authenticity Guarantee for Jewellery

Diamond clarity

GIA evaluates disclosed clarity grades for diamonds that are 0.15cts or larger, as long as the mounting allows. The clarity grades that are eligible for verification are VS2, SI1, SI2, I1, I2 and I3, while the clarity grades FL, IF, VVS1, VVS2 and VS1 will not be verified. The tolerance for all stated clarity grades is -1 grade. For example, a stated clarity grade of SI1 will pass verification if the apparent clarity is SI2.

NOTE: If the stated clarity grade falls in the FL-VS1 range but the clarity is obviously lower, the item will fail verification.

Diamond colour

For colourless diamonds, Jewellery experts will verify the listed colour value and accept a –2 tolerance from the lowest value indicated. For example, if a listing states the colour is G and the expert determines the colour is likely I, the diamond will pass colour verification. Similarly, if the listing states the colour is J-K and is likely L-M, the diamond will pass colour verification.

Please note, D-Z diamonds with a weight below 0.25ct will not be verified for colour.

Please note the colour of the setting may impact the appearance of the diamond (i.e. a diamond set on yellow gold may appear less clear).

If a seller states that a diamond has a fancy colour grade (e.g. Fancy Light Pink), the diamond’s basic hue will be verified as long as the mounting allows but the level of saturation will not be verified. 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”.

In some cases, a diamond has a fancy hue that the seller does not disclose. In such cases, the stated D-Z grade will not be verified.

• If the hue is brown or grey, the buyer will be informed and given the chance to accept or reject the item.
• If the hue is anything other than brown or grey (e.g. pink, blue, etc.), the item will pass verification.

Diamond Treatment

A Diamond expert will verify if a particular treatment is present or not in the diamond as well as the nature of the treatment to assess its stability. The results will be verified against the listing and depending on whether the details about the treatment are disclosed or not, the expert will proceed as follows:

• If the listing makes no statement about treatment but any other stable/permanent treatment is present, listing will pass verification.
• If the listing makes no statement about treatment but any other unstable/non permanent treatment is present, the buyer will be contacted for approval.
• If the listing states unstable treatment, GIA will not verify clarity and colour on this item. GIA will not verify colour treatments for both D-Z and coloured diamonds.

E.g.:

• Fracture filling: not permanent or stable
• Laser drilling: permanent

Coloured stones colour

For coloured stones, experts will confirm basic hues. Any trade term which describes specific colours and qualities of gemstones that are typically assigned to gemstones of superior quality and rarity such as Royal blue, Pigeon blood or Padparadscha will not be verified.

Coloured stones creation

The creation of coloured stones will not be verified if the total carat weight for the species is less than 0.20cts.

Example: A necklace features three rubies with a stated weight of 0.05cts each. The stated total carat weight for the species is 0.15cts. The creation of the rubies will not be verified.

Carat weight

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%.

GIA will not assess the accuracy of carat weight disclosures for individual stones set in jewellery and weighting under 0.20 cts, or for an aggregate stone weight under 0.20 cts.

Assembled stones

Assembled stones are stones constructed out of two or more materials and are not eligible for Jewellery 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 coloured cement.

Item size

An expert will verify that the size of the item matches the size listed by the seller (i.e., inches, mm) or the size of any ring. Necklaces have a tolerance of +/- 1 inch. Bracelets and anklets have a tolerance of +/- ½ inch . Rings will have a tolerance of +/- 1 full ring size. Bangle size will not be confirmed.

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).

Gemstone treatments

Gemstones that are eligible for Authenticity Guarantee are commonly treated. Clarity enhancements can be performed on any stone that has a fracture but is more common in some gemstones than others.

Please note coloured diamond treatments will not be verified.

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

Please note, clarity enhancements can be performed on any stone that has a fracture but is more common in some gemstones than others.

Gemstone treatment definitions

• Heating: Heating a stone at temperatures that may vary from 300C to 1800C (depending on the stone) to change the colour 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 sapphires 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 colour 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 colour, 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 colour.
• Coating: Applying a foreign material to the outside of a gemstone to change its colour. This treatment is usually not permanent.
• Dyeing: Filling fractures or openings at the surface of a stone with a foreign coloured material to create an artificial colour.

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 coloured stone. Some blue topaz is assumed to be treated because of its depth of colour.
• Beryllium diffusion: Can be detected but only with sophisticated chemical analysis.
• Additionally, claims that coloured stones are untreated will not be verified.

Undetermined results

In some cases, if it’s not possible to determine whether an item is unstable, lab-created or has been treated using then-current techniques and technology, treatment status of the item is undetermined and will pass this verification step.

The creation of coloured stones will not be verified if the total carat weight for the species is less than 0.20 cts.

Example: A necklace features three rubies with a stated weight of 0.05 cts each. The stated total carat weight for the species is 0.15 cts. The creation of the rubies will not be verified.

The natural or laboratory-grown origin of all varieties of quartz cannot be determined under Authenticity Guarantee.

Country of origin will not be verified for any gemstone.

Pearl

Pearl verification is focused on the determination that the material being verified is in fact pearl, rather than an imitation (e.g. fashioned shell, coated plastic, glass bead, etc.). A reasonable effort will be made to verify the accuracy of any claim regarding the shape, colour and size of a pearl.

• Items with 10 or less pearls = we verify all pearls
• Items with 10 or more pearls = we will select at random a range of 5 - 10 pearls to verify

Mounting limitations

If a mounting prevents us from separating pearls from Mabe/assembled pearls without advanced testing: we will use the term mollusk nacre materials for these items.
Claims that will not be verified:

• Any claim that a pearl is "cultured" or "natural".
• Any claim that a pearl originated in a specific environment (saltwater vs. freshwater)
• Any claim of treatments, trade terms and mollusk species.
• Any claim of classification or grades

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 Jewellery 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.

Gold Plating

Gold plating and the base metal will be verified; however, the purity of the gold plating cannot be determined under Authenticity Guarantee.

Metal purity

The alloy of any metal may be inconsistent between different areas of a jewellery piece. For each jewellery item, GIA tests one or more areas of the metal at random for metal type and purity.

The following metals and metal purities are eligible for verification.

Please note, resizing an item may result in undisclosed composition and colour variation 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: Please note there is no negative tolerance on purity.

Gold purity conversion chart

Gold must be at least 9ct to be eligible

Tolerance: Please note there is no negative tolerance on purity

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).

Please note, purity range below 850 will not be verified.

Tolerance: Please note there is no negative tolerance on purity.

Palladium purity conversion chart

Palladium = Pall., Pd. or Palladium if preceded by a number indicating parts per thousand of pure Platinum.

Please note, purity range below 500 will not be verified.

Tolerance: Please note there is no negative tolerance on purity.