Constituent
- Name
- Talc
- IMA name
- Talc
- Class
- silicate mineral
- Compound type
- phyllosilicate
- Relevance
- main - major
- Arrangement
- single phase
- Mass fraction
- 1.0
- Formula
- $Mg_3Si_4O_{10}(OH)_2$
- Chemical formula
- Mg3Si4O10(OH)2
- Elemental formula
- Mg3 Si4 O12 H2
- Isotope mixture type
- terrestrial abundance
- Oxides
-
Formula $MgO$ $SiO_{2}$ $H_{2}O$ Mass fraction (%) 31.88 63.37 4.75
Strunz
- Class
- silicates (09)
- Division
- phyllosilicate (09.E)
- Family
- Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets (09.EC)
- Code
- 09.EC.05
Dana
- Major class
- silicates (VIII)
- Class
- phyllosilicate sheets of six-membered rings (71)
- Type
- with 2:1 layers (71.02)
- Group
- Pyrophyllite-talc group (71.02.01)
- Code
- 71.02.01.03
- Phase type
- crystalline
- Crystal system
- monoclinic
- Crystal class
- prismatic
- Crystal class symbol
- 2/m (C2h)
- Crystal spacegroup
- C2/c
- Texture
- monocrystalline
- Molar mass
- 379.27 $g/mol$
- Density
- 2.7 - 2.8 $g/cm^3$
- Refringence type
- biaxial
- Refringence sign
- negative
- Birefringence
- 0.037 - 0.05
- Refraction index $n_{\alpha}$
- 1.538 - 1.55
- Refraction index $n_{\beta}$
- 1.575 - 1.594
- Refraction index $n_{\gamma}$
- 1.575 - 1.6
- Color
- pale green, white, gray white, yellowish white, brownish white
- Diaphaneity
- translucent
- Luster
- vitreous