Tantalite

الوصف

~~Axial Ratios:  a:b:c =0.**9:1:0.***3 
Help on Cell Dimensions: Cell Dimensions:  a = 5.**2, b = *4.**5, c = 5.**7, Z = 4; V = **5.*6 Den(Calc)= 8.*0 
Help on Crystal System: Crystal System:  Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pcan 
Help on X Ray Diffraction: X Ray Diffraction:  By Intensity(I/Io): 2.*9(1), 3.*9(0.9), 2.*1(0.7), 

~~{**0} Imperfect 
Color:  Black, Brown. 
Density:  8.1 
Diaphaneity:  Opaque 
Fracture:  Brittle - Uneven - Very brittle fracture producing uneven fragments. 
Crystalline - Fine - Occurs as well-formed fine sized crystals. 
Disseminated - Occurs in small, distinct particles dispersed in matrix. 
Massive - Granular - Common texture observed in granite and other igneous rock. 
Hardness:  **6.5 - Orthoclase-Pyrite 
Luminescence:  Non-fluorescent. 
Luster:  Sub Metallic 
Streak:  brown