Pliny identifies the most valuable gemstone as being ‘adamas’ which ‘for long was known only to kings, and to very few of them’. In Greek, adamas means unconquerable or invincible. The characteristic of adamas is that it is exceptionally hard. Some scholars consider that Pliny was talking about diamonds here and it is clear that the word ‘diamond’ derives from the Greek adamas. However, he goes on to describe six different types of ‘adamas’, only two of which are probably diamonds – transparent, octahedral crystals that resemble rock crystal. It is worthwhile remembering that the diamonds that Pliny might have seen were uncut, natural stones as the skill of diamond polishing did not occur until around 1496. The other four types of adamas listed by Pliny are silvery in colour and were usually found with gold.

Diamond set beehive ring

Pearls from Arabia and India are the second most valuable gemstone which Pliny discusses further in his ninth Book. Third in value are the ‘smaragdus’ which are green stones. Pliny lists twelve kinds of green ‘smaragdus’ from different locations such as Bactria (a Greek state occupying areas such as part of Iran and Afghanistan), Scythia (around northern Iran and further north), Egypt, Cyprus, Ethiopia, Media (another part of Iran), Attica and Persia. One or two of the stones Pliny describes are clearly emeralds, but others, which he states are found in copper mines, appear to be malachite, dioptase, jasper, and chalcedony. The word ‘smaragdus’ evolved into the word ‘emerald’.

Collection of green gemstones

Pliny notes that ‘[beryls], it is thought, are of the same nature as the smaragdus, or at least closely analogous’, which, as we know, was quite correct as they belong to the same family. He states that they are mined in India and are usually cut to a ‘smooth hexagonal shape’. Beryls came in a range of colours, with the most esteemed one being the colour of the pure green of the sea (aquamarines).

Beryl (aquamarines)

The next valuable gemstone is the opal which is also mined in India. Pliny describes them as displaying ‘the more subtle fires of the “carbunculus”, the flashing purple of the amethyst and the sea-green tint of the “smaragdus”, all combined together in incredible brilliance’ – rather a beautiful description.

Signet ring set with sardonyx

It is when we arrive at this section of the Book that Pliny announces that these gemstones talked about above have been chosen as valuable by women, or as one scholar translates it, ‘by decree of our Women-councillors of State’ and another scholar as ‘by the ladies’. There are only three stones that men chose as valuable, often only because another man might value them – sardonyx, onyx and sard. All are forms of chalcedony quartz, are translucent, have a dull or waxy lustre, and usually display some type of banding, though it can be quite indistinct. Those with distinct banding are called agates. We know onyx today as black but onyx is actually a parallel banded chalcedony agate with, usually,  bands of black or dark brown and white. When the parallel bands are reddish brown or dark orange and white, the stone is called ‘sardonyx, derived from two words, ‘sard’ and ‘onyx’. ‘Sard’ is said to be named after the ancient Persian city of Sardis, where this reddish brown/dark orange and white layered agate was mined.

Next week, I will look at gemstones grouped by colour.