Materials

These transparent gypsum crystals were known in ancient times as ‘Lapis specularis’. Lapis specularis is crystallized gypsum that the Romans used for their windows.

The crystals allow the light to pass, hence the Latin name: ‘Lapis' (stone) and 'speculo' (mirror).

This mineral was the economic engine for an entire region in Hispania (Spain) for almost a century and a half. This economy collapsed when a technique was invented to make larger rectangles from glass.

Here is a small selection of the available minerals & crystals: white opal (described by Pliny the Elder), citrine (very expensive in antiquity), red jasper, blue agate, amethyst, sodalite, aquamarine blue, ...

Naturally formed crystals grow in different shapes, colors, shades of color, ...

In antiquity these stones were used for jewelry, dye, raw material, healing properties, ...

Obsidian (volcanic glass), millstone, flint/silex, horn, bone, ivory, a piece of meteorite from the Kamil crater, copper, iron, ...

The first Greek word for iron is ‘sediros’ (= of the stars), because the first metal objects were produced from meteorites, which contain a lot of iron.

The arsenic in arsenic bronze has cost the life of many blacksmiths.

Ever seen poisonous arsenic? Looking at it is fine (see the dark spots), touching is strongly discouraged.

Which link applies between these grayish, cubic-shaped galena crystals from the mines of Laurium and this shiny Greek coin?

The ancient miners were very thorough and that's why these days such large galena crystals from Laurium are rare. I was lucky to acquire this find from the private collection of an old collector, who in turn acquired this crystal from a collector long ago.