Dealing in natural spinel, garnet, tourmaline and more


Menahem Sevdermish
CEO and President of GemeWizard, Ramat Gan, Israel
Interview with Menahem Sevdermish, CEO and President of GemeWizard, Ramat Gan, Israel
The range of Tanzanian gems’ lovely colours — both natural and slightly treated — is Mr Sevdermish’s particular passion. The intense bright orange of natural spessartite, the pink and pastel shades of spinel and the falling-leaves colours of “autumn” tourmalines cause him to wax enthusiastic.  The latter shades coincide with the current fashion for earth tones in cosmetics and are hot sellers in today’s market.  These natural stones, plus some of the rarest natural-colour tanzanite “on the planet”, have caused him to adopt the slogan, “You look your best when you’re natural”.

Mr Sevdermish is excited about the recent discovery of a small number of tanzanites with unusual pleochroism from the Merelani Hills. These combine colours not normally seen together in one piece of rough, such as green, violet and blue, or green, violet and yellow. Green and violet, he points out, are not even near to each other in the spectrum, making this rough tanzanite gemmologically rare. When he cuts and polishes such a piece, it results in a beautiful finished product such as a heart shape with blue curves and a green interior.

Tanzania is producing fabulous gem colours in important quantities, including zircons that “open up their colours” with a little heating. He believes that these gems will catch on because jewellers are looking for novelty without high expense. He also credits the Internet with encouraging buyers, sellers and designers to seek out new styles.

Mr. Sevdermish talks about a phenomenon in the gem trade where having a small amount of a relatively new gem - say, spessartite - available for sale actually works against the usual theory that rarity equals high value. This is because a somewhat rare but inexpensive specimen might be overlooked by jewellers and not used in their designs.  When that stone begins to appear on the market in larger quantities, jewellers take note and incorporate it into designs and catalogues; the resulting interest translates into demand and pushes prices higher.

Mr. Sevdermish is one of the leading Israeli coloured gemstone dealers, cutters and experts. He has been buying, cutting and selling coloured gemstones for decades and has focused on unique stones with exciting colours. He is also the inventor of GemeWizard, a computer software program for grading coloured gemstones, as well as a provider of pricing information and an internet trading platform. In his interviews Mr. Sevdermish discusses natural-colour gemstones, Tanzanian gemstones, Tanzanian production and unique tanzanite colours.