Authenticity Promise

Every Farangems stone is natural, and every treatment is disclosed. This page explains exactly how we make that promise, how we test, and what happens if a laboratory ever disagrees with us.

Our promise

We sell natural gemstones only. We do not stock synthetic (lab-grown) stones, simulants, glass-filled, lead-glass-filled, diffused, coated or dyed stones. If an independent, recognised gemological laboratory ever finds that a stone you bought from us differs materially from our description, whether in identity, natural origin or treatment, we will refund the full purchase price including shipping and the cost of the report, with no time limit.

How we check every stone

Sourced in person. We buy directly from cutters, miners and trusted dealers at the Jewelry Trade Center in Bangkok, through our Peshawar office, and at international fairs such as the Bangkok Gems & Jewelry Fair.
Identified at the bench. Each stone is examined under 10x magnification and tested with a refractometer, polariscope, dichroscope and UV lamp to confirm species and look for signs of treatment.
Documented honestly. Carat weight, dimensions, shape, origin and treatment status are recorded and published on the listing. Photos and videos are taken in daylight without colour filters.
Independent reports. Many stones already carry reports from independent labs. For any other stone, we can arrange a report before shipping on request.

Laboratories we work with

GIA: Gemological Institute of America
GRS: GemResearch Swisslab
AIGS: Asian Institute of Gemological Sciences, Bangkok
GIT: The Gem and Jewelry Institute of Thailand
Lotus Gemology: Bangkok

Report fees vary by laboratory and stone. Message us for a quote and turnaround time before you order.

Treatment glossary

No treatment / Unheated: no evidence of any treatment. The stone has only been cut and polished.

Heated: traditional heat treatment to improve colour or clarity, common for sapphire, ruby, tanzanite, zircon and some tourmaline. It is stable, permanent and widely accepted in the trade.

Oiled (minor / moderate): colourless oil or resin in surface-reaching fissures, standard practice for emerald. The degree is always stated.

Not sold by Farangems: glass-filled, lead-glass-filled, beryllium-diffused, surface-coated, dyed or synthetic stones.

Natural variation

Natural gemstones contain inclusions, the tiny crystals and fingerprints that formed with them. These are part of a stone's identity and are described in our listings. Colour can appear slightly different on different screens and in different light; if you are unsure, ask us for extra photos or a video before buying.