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.
These rubies comes from Thailand. If 90% of all rubies are heated to improve color, that one is not heated. It features a very strong color shift from vivd red to vivid purple.
This beautiful purple sapphire comes from the famous Ceylan source. Clarity is good and contrary to most of sapphires this stone was not heated to improve it’s qualities. This gem also present a rare and quite strong color change from purple to pink due to presence of both chromium and vanadium.
This small sapphire has a beautiful deep color. Despite it’s size it presents the interest to be unheated, but also to come from the region of Pailin, Vietnam. These mines unfortunately got controlled by the Red Khmer regime and became the first so called « blood gems ». Then the region returned to Vietnam. This source is now almost extinct and these stones become scarce.
A quite dark teal bluze sapphire from Ouest Africa, but presenting the particularity of being unheated.
A very small but nice champagne sapphire from the famous Umba Valley in Tanzania, with a nice color shift regarding the light source.
This amazing stone is very rare in several points. Under daylight it is reddish pink, and would almost be considered as ruby, but under incandescent it shift to purple. I consider it as a shifting pink sapphire. But it’s more spectacular quality is to display not one asterism but two. This phenomenon is the result of a twinning of two crystals and is very rare. The stone is untreated and comes from Sri Lanka.