Thursday, September 4, 2008

Facet grade musgravite from Tunduru, Tanzania

Musgravite is an extremely rare member of the taaffeite family that was discovered in 1967 in the Musgrave Range of South Australia.

Facet grade musgravite like pictured 5.93ct oval from from Tunduru, Tanzania -- was not reported reported until 1993 and as of 2005, there were only eight musgravite specimens, three of which were identified by Murray Burford, a Canadian gemologist. The mineral was has since turned up in Greenland, Madagascar, Antarctica, Sri Lanka, and Tanzania.

Because of its similarity to taaffeite it is probable that some gemstones originally thought by their owners to be taaffeites, are actually musgravites. Indeed, our own investigations of taaffeites from Tunduru, Tanzania, have confirmed a 10 – 15% incidence of stones originally indentified as taaffeites to actually be musgravite. The only known facet quality specimens of musgravite are from Sri Lanka and Tanzania. Musgravite is primarily sought as a collector gemstone.

Thursday, August 21, 2008

This month rare collectable gemstone finds

Taaffeite

Taaffeite is one of the rarest and most desirable of collector's stones. Only a very few stones have been found, most of them originally misidentified as spinel.

Sri Lanka and Tanzania appear to be the only sources for this material this time. Pictured 1.74 cts Taaffeite oval from Tanzania

However, because of the geological connection between the deposits in Sri Lanka, Madagascar, and East Africa, we expect to find the stones in Madagascar as well.

Poudretteite

Poudretteite is an extremely rare mineral that few gemologists have ever seen or even heard of. It was first discovered in Mont St. Hilaire, Quebec, Canada, during the mid 1960s.

Only seven crystals were unearthed but they were not recognized and registered as a new species until 1986. The mineral is named after the Poudrette family who operated a quarry in the Mont St. Hilaire area where the first specimens were discovered.

The only other reported source for poudretteite is in the Mogok region of the Shan state in northern Myanmar, and pictured 3.46cts fancy shape poudretteite from Myanmar is trully a rare find.