from
The Collaborative International Dictionary of English v.0.48
Topaz \To"paz\, n. [OE. topas, F. topaze, L. topazos, or
topazion, a kind of precious stone, Gr. to`pazos, topa`zion;
possibly akin to Skr. tap to glow (cf. {Tepid}). According to
some, the name is from Topazos, a small island in the Red
Sea, where the Romans obtained a stone which they called by
this name, but which is the chrysolite of the moderns.]
1. (Min.) A mineral occurring in rhombic prisms, generally
yellowish and pellucid, also colorless, and of greenesh,
bluish, or brownish shades. It sometimes occurs massive
and opaque. It is a fluosilicate of alumina, and is used
as a gem.
[1913 Webster]
2. (Zool.) Either one of two species of large, brilliantly
colored humming birds of the genus {Topaza} ({Topaza
pella} or {Topaza pyra}), of South America and the West
Indies.
[1913 Webster]
Note: The two tail feathers next to the central ones are much
longer that the rest, curved, and crossed. The Throat
is metallic yellowish-green, with a tint like topaz in
the center, the belly is bright crimson, the back
bright red. Called also {topaz hummer}.
[1913 Webster]
{False topaz}. (Min.) See the Note under {Quartz}.
[1913 Webster]