Thursday, August 1, 2013

Rare Gemstones III

Jeremejevite is a colorless, sky blue or pale yellow stone, the highest quality of which comes from Namibia. In nature it occurs in small obelisk-shaped crystals and has in the past been mistaken for aquamarine. It was named after Russian mineralogist Pavel Jeremejev who discovered the mineral in 1883.

Australia is the world's main supplier of opals. Almost 95 per cent of all opals come from Australian mines.
Alexandrite undergoes dramatic shifts in color depending on what kind of light it's in. A variety of Chrysoberyl, alexandrite belongs to the same family of gemstones as emerald. It's color-changing properties (and its scarcity relative to diamond) is due to an exceedingly rare combination of minerals that includes titanium, iron and chromium.

Tanzanite is found almost exclusively in the foothills of Mount Kilimanjaro. Like alexandrite, tanzanite exhibits dramatic color shifts that are dependent upon both crystal orientation and lighting conditions
Poudretteite - The first traces of poudrette were discovered in the mid 1960s in the Poudrette quarry of Mont Saint Hilaire, Quebec, but it wasn't officially recognized as a new species of mineral until 1987, and wasn't thoroughly described until as recently as 2003.

Jeremejevite was first discovered in Siberia at the end of the 19th century, gem-quality crystals of jeremejevite have since been recovered in limited supplies in Namibia. Pictured is the largest faceted jeremejevite on Earth, just shy of 60 carats (or roughly 12 grams).