or aventurin (əˈvɛntjʊrɪn) or avanturine (əˈvæntjʊrɪn)
noun
1.
a dark-coloured glass, usually green or brown, spangled with fine particles of gold, copper, or some other metal
2. Also called: sunstone
a light-coloured translucent variety of orthoclase feldspar containing reddish-gold particles of iron compounds
3.
a variety of quartz containing red or greenish particles of iron oxide or mica: a gemstone
Word origin
C19: from French, from Italian avventurina, from avventura chance; so named because usually found by accident; see adventure
aventurine in American English
(əˈvɛntʃərɪn)
noun
1.
a kind of glass flecked with spangles, as from copper filings or bits of chromic oxide
2.
a variety of chert that contains sparkling bits of mica, hematite, etc.
Word origin
Fr < It (vetro) avventurino, aventurine (glass): so named from resembling the mineral avventurina (< avventura, chance), so named from its rarity: see adventure