muscovite

noun

1. An inhabitant or native of Muscovy or Moscow.
2. (archaic, broadly)A Russian.
3. (countable, uncountable)A pale brown mineral of the mica group, being a basic potassium aluminosilicate with the chemical formula KAl₂(Si₃Al)O₁₀(OH,F)₂; used as an electrical insulator etc.

   “Do you enjoy the amber glow seen through the isinglass window of a wood stove? […] Muscovite (colorless, white, or pale red or green) mica is also common[…]; it was named for Moskva (Moscow), where much of Europe's mica was mined. Isinglass, mentioned above, consists of thin, transparent sheets of muscovite.”

adj

1. (not-comparable)Of or relating to Muscovy or Moscow, or the people of these places.
2. (not-comparable)Russian.