colorless glass made of almost pure silica

a hard glossy mineral consisting of silicon dioxide in crystal form; present in most rocks ( especially sandstone and granite); yellow sand is quartz with iron oxide impurities

A form of silica, or silicon dioxide ( SiO2), occurring in hexagonal crystals, which are commonly colorless and transparent, but sometimes also yellow, brown, purple, green, and of other colors; also in cryptocrystalline massive forms varying in color and degree of transparency, being sometimes opaque.

Quartzose.

A hard mineral composed of pure silica; the most common of solid minerals, found in many kinds of rock, often in the form of crystals.

A mineral composed of pure silica: rock- crystal.

A hard mineral, common in rocks, as in granite.

A mineral of pure silica.

A name applied to numerous varieties of rock- crystal of many shades of colour, or to crystallised silica, known under the various names of rock- crystal, amethyst, siderite, topaz, cairngorm, milk- quartz, rose- quartz, & c.

After finishing this task, I ascended the highest hillock on the shore, which consisted of strata of slate and quartz to admire the beauty of the prospect. – A New Voyage Round the World, in the years 1823, 24, 25, and 26, Vol. 2 by Otto von Kotzebue

He must have had a heart like rotten quartz – The La Chance Mine Mystery by Susan Carleton Jones

Some of the pieces had quartz among them. – Handbook to the new Gold-fields by R. M. Ballantyne

43. Q Quartz beds folded, i. – Himalayan Journals V2. by J. D. Hooker

Then there were hundreds of massive crushing- stones, neatly constructed out of blocks of basalt, which had been used for breaking the quartz lying in wild confusion amongst the ruined huts, and by the side of what once was a stream, but is now only a sandy, choked- up river- bed. – Southern Arabia by Theodore Bent Mabel Bent

He supposed they were composed of a species of quartz or mineral, but observing one of them within reach at his side, he reached upward with his knife and extracted it from the shale in which it was imbedded. – The Land of Mystery by Edward S. Ellis

On the summits are found conglomerates formed of quartz limestone, and sandstone. – Roumania Past and Present by James Samuelson

At the threshold they found two of the little Bulteels, playing with pieces of quartz crystal, etc. – A Simpleton by Charles Reade

There has been a great excitement here on account of the fancied discovery of valuable quartz mines in the vicinity of the American Rancho, which is situated about twenty miles from this place. – The Shirley Letters from California Mines in 1851-52 by Louise Amelia Knapp Smith Clappe

It's yonder in the new quartz country, you see. – Gold Seekers of '49 by Edwin L. Sabin

It must be remembered that in these mining districts the gold occurs in quartz reefs. – Impressions of South Africa by James Bryce

Luck found gold first, but in so small a vein of quartz that we did not consider it worth working. – Spinifex and Sand Five Years' Pioneering and Exploration in Western Australia by David W Carnegie

If quartz prisms and lenses be used, and the electric light be the source of illumination, the ultra- violet spectrum will extend to an enormous extent. – Colour Measurement and Mixture by W. de W. Abney

The quartz apparently paid admirably. – The Shirley Letters from California Mines in 1851-52 by Louise Amelia Knapp Smith Clappe

Not so much quartz today although large piles of it are to be seen. – McKinlay's Journal of Exploration in the Interior of Australia by John McKinlay

And that ain't glass in there- and it ain't quartz in in there- and there's only one man ever in this country ever had a bridle like that. – The Heritage of the Hills by Arthur P. Hankins

Some little girls' rooms are naturally orderly, I suppose; or I don't know how they could live in them, if they cry out so when they only see quartz crystals in confusion. – The Ethics of the Dust by John Ruskin

This quartz gravel, with its mixture of gems, rests upon a stiff white pipe- clay. – Eight Years' Wandering in Ceylon by Samuel White Baker

The quartz veins also lie in this general course, one of which may be traced hundreds of miles. – Journal of a Trip to California by the Overland Route Across the Plains in 1850-51 by E. S. (Eleazer Stillman) Ingalls