This collection presents mostly « rare gems » or « collector gems », more often not used in jewellery because of rarity or hardness. Rarity is due to  the quantity available, or a rare color, source or inclusion, or the difficulty to cut the rough into a faceted gem. Microphotographies are taken with an old Olympus microscope and an iphone. These gems are not for sale, but some extra specimens may be available. The collection is visible but stored in a specific location, so please contact me for an appointment.

Among the most famous of precious gem, corundum is divided in two different gems regarding the color. Red and pinkish red is named ruby, and all other colors, from blue to yellow, orange, purple, pink or colorless are named Sapphire. Some specimens present a color change regarding the light source. On the market 80-90% of the sapphires and rubies are heated to enhance the color and clarity. Unheated gems become scarce. The most famous sapphires come from Kashmir but some come from South America, some rubies were found in Ticino regio, Switzerland.