Midge included in amber from the Baltic coast, polarised light
Inclusions of chrysotile fibres in demantoide garnet from Ural Mountains, Russia
Inclusions of hematite in feldspar (sunstone), India
Dendrites in agate
Epigenetic inclusion (probanly melanterite) in quartz, Brazil, parallel polarisers
Spinel crystal in dolomite marble, Burma
Inclusions of rock crystal and rutile needles in quartz, Brazil, polarised light
Two-Phase inclusions and rutile needles in rock crystal from Brazil


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.