Accuracy and limitations

What photos can support

• Visible colour, transparency, cut style and surface condition
• Plausible identities and common look-alikes
• Advice on better photos and useful next tests

What photos cannot establish

• Natural versus laboratory-grown origin
• Treatments such as heating, filling, dye or stabilisation
• Country of origin, carat weight, formal grades or value
• Metal fineness or exact age

Common myths we avoid

• A normal photo does not measure refractive index or chemistry.
• No visible inclusions does not prove a stone is synthetic.
• Inclusions do not automatically prove natural origin.
• Seller location is not geological provenance.
• A metal stamp does not authenticate a mounted stone.

Accuracy figures

We do not publish accuracy percentages. They require evaluation on independently labelled specimens, which has not yet been done. All categories are experimental.