Sphene Thin Section

Sphene is a collector s gem and is particularly rare when you start talking about a clean stone above 5 carats the international gem society says.

Sphene thin section. Titanite catisio5 c 2001 mineral data publishing version 1 2 crystal data. Three small hand samples sphalerite on fossiliferous chert. Titanite is an orthosilicate with independent sio 4 tetrehedra united by ti 4 in octahedral coordination and ca 2 in sevenfold coordination.

As a gemstone titanite is usually some shade of chartreuse but can be brown or black. Sphalerite in thin section thin section gigapans. When viewed in thin section with a petrographic microscope pleochroic halos can be observed in minerals surrounding a titanite crystal.

Physical properties chemical formula catisio5 class nesosilicate isolated tetrahedra crystal system monoclinic habit spheroidal crystals tabular massive lamellar normally fine grained. A 20 96 carat sphene from mayer watt. Titanite or sphene from the greek sphenos σφηνώ meaning wedge is a calcium titanium nesosilicate mineral ca ti si o 5 trace impurities of iron and aluminium are typically present.

It is also alternatively called titanite for its titanium content. Calcium may be partly replaced by thorium. Sphene is a source of titanium dioxide tio2 used in pigments.

Also commonly present are rare earth metals including cerium and yttrium. As is the case with all gemstones size creates a premium with this species. Spinel thin section photomicrographs are taken in plane polarized light and cross polarized light and can easily be recognized under the microscope.

Titanite sphene catisio 5 sphene is named from the greek word sphenos for wedge because of its typical wedge shaped crystal habit. Occasionally occurs as fine crystals color gray black brown greenish yellow hardness 5 to 5 5 specific gravity 3 50 cleavage good prismatic 110 poor 100 fracture uneven luster adamantine transparency. Sphalerite in hand sample.