| Mineral | TALC |
| Chemistry | Mg 3 Si 4 O 10 (OH) 2 |
| Class | Silicates |
| Uses | an ornamental and heat, acid and electrically-resistant stone (soapstone) used as counter tops, electrical switchboards, carvings, etc, used as an ingredient in paints, rubber, roofing materials, ceramics and insecticides. Most commonly known as the prima |
| Color | Translucent Colourless white Pale Green brown |
| Luster | WaxyPearly |
| Transparency | crystals are translucent and masses are opaque. |
| CrystalSystem | Triclinic |
| CrystalHabits | : never in large individual crystals, but if found are flattened tabular crystals with a hexagonal cross-section, usually talc is found in compact or lamellar masses.Forms pseudomorphs (false shape) of other crystals such as quartz, pyroxenes, olivine and amphiboles. |
| Cleavage | Perfect (100) |
| Fracture | perfect in one direction, basal. |
| Hardness | 1 |
| Characteristics | cleavage flakes are slightly flexible but not elastic and talc has a soapy feel to the touch. |
| Indicators | softness, color, soapy feel, luster and cleavage. |
| DensityNote | average |
| IMAStatus | Approved |
| CellParameters | a = 5.29b = 9.173c = 9.46 α=90.46°β=98.68°γ=90.09° |
| Ratio | a:b:c = 0.577 : 1 : 1.031 |
| OpticalType | Biaxial (-) |
| RI | n α =1.538 - 1.550 n β =1.575 - 1.594 n |
| Birefringence | δ=0.037 - 0.050 |
| SurfaceRelief | Moderate |
| Strunz | 8/H.09-40 8 : Silicates H : Phyllosilicates (layered)Tetragonal or pseudotetragonal layered structures [Si4O10]4- and others 09 : Talc series |
