The Greeks and Romans believed that rock crystal was a form of fossilized ice. According to Aristotle and the ancient naturalists, glass too, was a mineral, at the basis of which lay an aqueous emission: this property made it similar to the more noble crystal.

Fifteen centuries before the celebrated Venetian discovery of crystal-glass, the purity and transparency of rock crystal, for Roman craftsmen, was the model on which to mould working techniques and glass production. Numerous literary testimonies of the I century A.D. attest to the appearance of cups and other articles made of rock crystal on the tables of patricians who could afford to spend astronomical sums to purchase luxury objects.

The Greeks and Romans also understood that rock crystal had greater refractive properties than glass, and that this mineral could be used to made magnifying glasses, prisms and burning-globes.