Muscovite
“The transparent mica”
Muscovite is a common, silvery-white mica mineral that splits into thin, flexible, transparent sheets. Before glass was widely available, large sheets of muscovite were used as window panes in Russia — a practice that gave the mineral its name, derived from 'Muscovy' (Moscow).
potassium aluminum silicate hydroxide (KAl₂(AlSi₃O₁₀)(OH)₂)
Minas Gerais (Brazil), Bihar (India), Spruce Pine (North Carolina, USA), Kola Peninsula (Russia), Madagascar
2-2.5
Muscovite is so heat-resistant that it was used as peep-hole windows in furnaces and stoves for centuries, and today it serves as an insulator in electronics and electrical equipment.
Test Your Knowledge
Why is muscovite mica a critical component in high-voltage electrical insulation?
Related Specimens
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