Muscovite
| Colour | Clear, Brown, White |
|---|---|
| Mohs hardness | 2–2.5 parallel to {001} 4 right angle to {001} |
| Lustre | Vitreous, silky, pearly |
| Streak | White |
| Crystal system | Monoclinic |
| Transparency | Transparent to translucent |
| Cleavage | Perfect on the {001} |
| Fracture | Micaceous |
| Chemical formula | KAl 2 (AlSi 3 O 10 )(F,OH) 2 |
| Specific gravity | 2.76–3 |
What is Muscovite?
Muscovite (also known as common mica, isinglass, or potash mica) is a hydrated phyllosilicate mineral of aluminium and potassium with formula KAl2(AlSi3O10)(F,OH)2, or (KF)2(Al2O3)3(SiO2)6(H2O). It has a highly perfect basal cleavage yielding remarkably thin laminae (sheets) which are often highly elastic. Sheets of muscovite 5 by 3 meters (16.4 ft × 9.8 ft) have been found in Nellore, India.
How to identify Muscovite
- Lustre: Vitreous, silky, pearly.
- Hardness: Mohs 2–2.5 parallel to {001} 4 right angle to {001} — soft; a knife will scratch it.
- Streak: White.
- Habit: Monoclinic crystal system.
Muscovite in different forms
Stones often confused with Muscovite
Frequently asked questions
How hard is Muscovite?
Muscovite is Mohs 2–2.5 parallel to {001} 4 right angle to {001} on the hardness scale.
What colour is Muscovite?
Muscovite is typically clear, brown, white (White, grey, silvery).