natural glass

English Thesaurus

1. magma of any composition that cooled very rapidly (noun.substance)

hypernym	:	glass,
definition	:	a brittle transparent solid with irregular atomic structure (noun.substance)

hyponym	:	crystal, lechatelierite, quartz, quartz glass, vitreous silica,
definition	:	colorless glass made of almost pure silica (noun.substance)

hyponym	:	tektite,
definition	:	thought to derive from meteorites (noun.substance)