( n. )
A mineral having a glassy fracture, occurring in translucent trapezohedral crystals. It is a silicate of alumina and potash. It is found in the volcanic rocks of Italy, especially at Vesuvius.
( n. )
A mineral having a glassy fracture, occurring in translucent trapezohedral crystals. It is a silicate of alumina and potash. It is found in the volcanic rocks of Italy, especially at Vesuvius.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012