Talc is an aqueous magnesium silicate.
It contains 63.5% SiO 2 , 31.7% MgO and 4.8% H2O in its ideal composition.
It is in white, greenish transparent colours, slippery, massive and soft.
Its hardness varies between 1-1.5 according to the Mohs scale.
Its density is between 2.6-2.8 gr/cm3.
The crystal shape is monoclinic.
Talc has poor thermal and electrical conductivity, but is fire resistant.
It hardens, solidifies when heated at high temperatures.
It does not degrade with acids.
Commercial talc often differ considerably from theoretical purity.
Such products may be in the form of pure talc minerals as well as mixtures of minerals such as dolomite, calcite, quartz, diopside, serpentine, magnetite, pyrite, tremolite-actinolite and mica found in the paragenesis of talc and talc in different proportions.
Packaging: 1 kg (2,20 lb) - 25 kg (55,12 lb)
Types of commercial talc include:
Soapstone (Soapstone): It is the naming of the massive form containing mineral talc.
It contains at least 50% mineral talc, has resistance to electricity and acids, and has heat-resistant properties.
Steatitis:
It is a term used for high purity solid talc.
The most common usage area is the construction of electrical insulators.
Lava:
It is used to refer to block talcs or end products obtained from block talcs.
Asbestos:
Pure talc mineral is rarely fibrous in its crystalline properties.
Asbestos, on the other hand, is more like sheet, sheet, or mica.
Rensselaerite:
It is a mineral similar to talc but soft and not greasy.
French Chalk:
It is a massive variety of talc and is used in paint and pencil production.
Physical Properties of Talc
Color: Green, gray and silvery white.
Luster: Dull like frosted or oily.
Transparency: Crystals are translucent, the mass is opaque.
Crystal System: Monoclinic. (2/m.)
Crystal Behavior: Generally, talc is found in compact or leaf-shaped masses. Quartz takes the false form of other crystals such as pyroxene, alivine, and ampibol.
Cleavage: Perfect in one direction.
Hardness: 1.
Specific Gravity: 2.7-2.8. (Average)
Vein: It is white.
Other Characteristics: The cleavage pieces are slightly pliable, but not elastic. Talc feels like soap when touched.
The best defining features:
It is softness, colour, soapy feel, shine and cleavage.
Talc; It is used in ceramics, paint production, roof coating, pesticide production, rubber and paper industry, cosmetics and pharmacology, asphalt filler production, animal feed and fertilizer production.
According to the intended use, softness, oil absorption, moisture content, melting point, specific gravity, heat and electrical conductivity and chemical analysis are important.