Very fine Roman intaglio

A rather noble looking woman wearing what I thought to be a small modius on her head , but is more likely a lunar crescent, and what appears to be the top of a quiver of arrows behind her shoulder...... so representation of Diana. (Thanks to Steve for pointing this out).

This green stone may be either an unusually transparent green jasper or indeed quite possibly the very rare gemstone, peridot.


The gemstone known to the ancient Greeks and Romans as topazos is the modern peridot, the gem variety of the mineral olivine ([Mg, Fe]2SiO4).
This mineral varies from transparent to translucent and, as its name implies, typically has an olive-green colour.
This gemstone was used rather infrequently in the Mediterranean region during the Hellenistic and Imperial Roman periods, with known artefacts ranging in age from 250 BC to AD 500.
Most of these are plain or intaglio-cut stones for finger rings .
The only known ancient source of peridot is Zabargad (also known as Saint John's Island), off Egypt's southern Red Sea coast
The Greek historian and geographer Agatharchides of Cnidos (writing in the mid 2nd century BC but using 3rd-century BC sources) said that topazos was best found just after sunset, giving rise to the name 'evening emeralds', which is sometimes applied to peridot today

Intact
16mm


Very interesting article, by James Harrell of the University of Toledo and Elizabeth Bloxam of London University College, which originally appeared in MINERVA magazine.

http://www.palagems.com/zabargad.htm