Term: obsidian: acid or granitic glass formed by the rapid cooling of lava without crystallization; usually dark, but transparent in thin pieces
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: angel shark: sharks with broad flat bodies and winglike pectoral fins but that swim the way sharks do
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: historic period: an era of history having some distinctive feature
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: meagerness: the quality of being meager; -George Eliot
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: terbium: a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: rosette: a cluster of leaves growing in crowded circles from a common center or crown (usually at or close to the ground)
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: planter: the owner or manager of a plantation
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: throatwort: European bellflower with blue-purple to lilac flowers formerly used to treat sore throat
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: perdix: a genus of Perdicinae
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: grave: death of a person
Broader: volcanic glass: a kind of natural glass produced when molten lava cools very rapidly | Unrelated: underpart: a part lying on the lower side or underneath an animal's body