Structure in a healing fissure in topaz from Brazil
Dendrites in agate
Twin-crystal of chrysoberyl
Inclusions of rutile (dark crystal and fine needles) and clusters of zircon grains in umbalite garnet, Tanzania
Two-phase inclusions in sapphire, Sri Lanka
Inclusions of hematite in aquamarine, Tanzania
Epigenetic inclusion (probanly melanterite) in quartz, Brazil, crossed polarisers
Fluid inclusions in quartz with bituminous daughter minerals, China


Company Members
Swiss or Liechtenstein companies registered on the commercial register and who belong to the precious stone, jewellery and watch industry or gemmological laboratories can become members of SGS.

Active Members

Those who work in the jewellery and watch industry, the gemstone industry or one of the gemmological laboratories and who hold a gemmological title for diamonds and coloured gemstones can be accepted as active members after attending a regional seminar and a central continuing education course. The following titles are recognised: SSEF, GIA, FGA or the German Gemmological Society.

Expert SGS

An active member can deepen his gemmological knowledge and obtain the diploma, which allows the legal title "SGS precious stones expert" to used.

Candidate Members

Interested persons without a gemmological title can be accepted as candidate members. The person concerned may continue their gemmological training and should have the possibility to acquire the gemmological titles for diamonds and coloured gemstones / pearls within five years in order to become an active member of the society.


People who are interested in Gemmology may participate at any time in the continuing education courses of both the regional groups and /or the Central Continuing Education Courses. One is able to pay a participation fee for each course without any obligation to the SGS.


For further information, please contact us on: nfgmmlgch.