General Information
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| Chemical Formula: |
CaTiSiO5 = CaTiOSiO4 |
| Composition: |
Molecular Weight = 196.04 gm |
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Calcium 20.44 % Ca 28.61 % CaO |
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Titanium 24.42 % Ti 40.75 % TiO2 |
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Silicon 14.33 % Si 30.65 % SiO2 |
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Oxygen 40.81 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OxIDE |
| Empirical Formula: |
CaTiSiO5 |
| Environment: |
Magmatic, metamorphic and hydrothermal rocks. |
| IMA Status: |
Approved IMA 1960 |
| Locality: |
Laacher See and Eifel, Germany. Madagascar |
| Name Origin: |
Named after its chemical composition of titanium. |
| Synonym: |
Sphene, titanite |
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Titanite Image
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  Click on the picture to go to Sphene crystal.
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Crystallography
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| Axial Ratios: |
a:b:c =0.7522:1:0.8532 |
| Cell Dimensions: |
a = 6.56, b = 8.72, c = 7.44, Z = 4; beta = 119.716ø V = 369.62 Den(Calc)= 3.52 |
| Crystal System: |
Monoclinic-Prismatic H-M Symbol (2/m) Space Group: P21/a |
| x Ray Diffraction: |
By Intensity(I/Io): 3.233(1) 2.595(0.9) 2.989(0.9) |
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Physical Properties
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| Cleavage: |
[110] Distinct, [100] Imperfect, [112] Imperfect |
| Color: |
reddish brown, gray, yellow, green, or red. |
| Density: |
3.4 - 3.56, Average = 3.48 |
| Diaphaniety: |
Transparent to translucent to opaque |
| Fracture: |
Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces. |
| Habits: |
Massive - Lamellar - Distinctly foliated fine-grained forms., Crystalline - Fine - Occurs as well-formed fine sized crystals., |
| Hardness: |
5-5.5 - Apatite-Knife Blade |
| Luminescence: |
Non-fluorescent. |
| Luster: |
Adamantine - Resinous |
| Streak: |
reddish white |
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Optical Properties
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| Optical Data: |
Biaxial (+), a=1.84-1.95, b=1.87-2.034, g=1.943-2.11, bire=0.1030-0.1600, 2V(Calc)=68-82, 2V(Meas)=20-56. Dispersion r > v extreme. |
| Pleochroism (x): |
colorless, greenish yellow, colorless, or yellowish brown. |
| Pleochroism (y): |
colorless, pink, greenish yellow, yellowish brown, or yellowish green. |
| Pleochroism (z): |
colorless, pink, reddish orange, pale yellow, or grass green. |
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Classification
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| Dana Class: |
Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O |
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with cations in [6] and/or > [6] coordination |
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Titanite group |
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- Titanite CaTiSiO5=CaTiOSiO4 P21/a 2/m
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Malayaite CaSnSiO5=CaSnOSiO4 A2/a 2/m |
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Vanadomalayaite CaVOSiO4 C2/c 2/m |
| Strunz Class: |
Silicates |
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Nesosubsilicates, with anions unfamiliar to tetraheders, cationes with coordinationnumber between [8] and [12] |
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STRUNZ - Silicates [Nesosubsilicates, with anions unfamiliar to tetraheders, cationes with coordinationnumber between [8] and [12 |
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- Titanite CaTiSiO5=CaTiOSiO4 P21/a 2/m
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Vanadomalayaite CaVOSiO4 C2/c 2/m |
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Malayaite CaSnSiO5=CaSnOSiO4 A2/a 2/m |
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- Trimounsite (Y) (Y,REE)2Ti2SiO9 P21/c 2/m
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