Ontario Mineral - Titanite (sphene)

Chemistry:

CaTiSiO5, Calcium Titanium Silicate

Class:

Silicates

Subclass:

Nesosilicates

Uses:

Mineral specimens, source of TiO2 (a pigment) and as a gemstone.

Color:

green, yellow, white, brown or black.

Luster:

adamantine.

Transparency:

Crystals are transparent to translucent.

Crystal System:

Monoclinic; 2/m

Crystal Habits:

include elongated wedges that form tabular or platy crystals. Some crystals are not so elongated and can have a trigonal appearance similar to a flattened rhombohedron. Twinning is common and produces a twin that is shaped like a deflatted, caved-in football, only with flatter surfaces.

Cleavage:

indistinct in two directions

Fracture:

conchoidal

Hardness:

5 - 5.5

Specific Gravity:

3.3 - 3.6

Streak

white

Other Characteristics:

Pleochroic if strongly colored.

Associated Minerals:

chlorite, anatase, calcite, quartz, zircon and feldspars.

Local Occurance:

Bear Lake Occurence, Bower's Point Roadcut, Burgess Corundum, Desmont Mine, Diamond Lake Roadcut, Musclow Occurrence, North Baptiste Lake Occurence, Saranac Mine

Best Field Indicators:

crystal habit, luster, hardness, twinning if present and color.

Description:

Sphene is named from the greek word for wedge, because of its typical wedge shaped crystal habit. It is also alternatively called titanite for its titanium content. Spene can be cut as gems although it is considered a rarity on the gem market. It brings to the table a fire greater than diamond and unique color shades. However its softness limits its desirability as a gemstone. Twinning is common in sphene and forms a classic twin shape that is found mostly in Pakistan. The twin is shaped like a deflated, caved-in football, only with flatter surfaces. Spene can form nice crystals and can make a lovely addition to the collection of a collector who appreciates different crystal forms.