A large number number of gemstones were known to many cultures during the medieval period. Which gemstones were known in which time and place is harder to ascertain. Such small precious goods could travel vast distances via trading, a trade which had been widespread in the time of the ancient myceneans (2000BC?), so it is only via the evidence of archeological finds and writings of gemstones that we can be sure which stones reached which cultures. Trade goods were more likely to reach prosperous outwards looking cultures than ones undergoing war, famine or internal unrest.
Many names occur for the same gemstones in medeival literature, making it difficult to identify the gemstone named. The same name may also be applied to several similar looking gemstones, eg carbuncle could refer to ruby or garnet.
Common gemstones (known in most times and cultures):
Rare gemstones (known to very few cultures and time periods):
Expensive gemstones (on average for most medieval times and places):
- amethyst (bigger discoveries in the modern period have brought the price down modernly, making it a good value choice for the modern reenactor)
- rock crystal
Out-of-period gemstones (or gemstones which were so excessively rare as to not have names in medeival europe):
- black opal
- jade (not availible in europe, rare in the middle east, common in china)
- tiger eye[]
Also fake gemstones (eg Carbachons - coloured glass jewels backed with metal foil) existed in medieval times, as a cheaper way to make things more ostentacious. They are more likely to be used in uses such as garments and belts, than on the crown jewel. Just remember that in some times glitz was popular with more being better, but in others obvious use of fake gems would mark one as a cheap tryhard, and a few fine pieces of real gems might be preferred. Ennamel could also be used to create brightly coloured blobs that pass for gems at a distance.
- ["On gemstones"]
- Lois Sherer "30,000 years of beads" Available from many places including Melbourne University Library