Quartz in the form of rock crystal occurs in all parts of the globe, and for the most part in well-formed crystals.
The windows were of rock crystal, but they could not be seen from without.
In the rough the diamond is less attractive in appearance than rock crystal.
rock crystal or quartz had long been employed to imitate diamonds.
The eyes consist of an iris of rock crystal, surmounting a metal pupil, and set in an eyeball of opaque white quartz.
It is by tasting them only that you can distinguish them from rock crystal.
At last they came to another door, made of crystal glass, and entered a large hall with a sparkling roof of rock crystal.
This exists in quartz and rock crystal in a nearly pure state.
rock crystal and asbestos are still found in the district of Paphos.
Flint glass is better, and rock crystal is better than flint glass.