The materials used for the manufacture of Aegean Seals
Hallo Fritz, you well?
Yes, all well here, I had been looking at some textbooks about seals and some more questions came up.
Hmmm... I very often see this distinction between soft and hard stone seals, and this seems to be very important for specialists... What do you mean by these terms?
Ok, yes... Look, Aegean seals are, as you know, often cut in stones. Among these stones there are those that are soft enough to be engraved by tools operated by hand (hand tools). Such stones are, for example, steatite, serpentine, chlorite, schist and calcite. These stones are found locally in the Aegean and are used for manufacturing seals from the very start of the Aegean Bronze Age through to its end!
This means that it was rather easy for the inhabitants of the Aegean to both get access to these materials and engrave them!
Hard stones on the other hand cannot be engraved by hand tools! These are some of the stones we call today semi-precious stones, such as cornelian, agate, chalcedony, amethyst, rock crystal, lapis lazuli and jasper. These materials are so hard that a special technique is required to carve them!
Yes, you cannot simply engrave them by, say, taking a knife and presenting it to their surface. Plus, while a few, like jasper, are found in the Aegean, most are not available there. So, in order to be used in the Aegean for making seals, it means that they had to travel there from areas outside it! Amethyst may, for example, have come from Egypt whereas the raw material of lapis lazuli came from as far as the Badakhsan region in Afganistan!
Hmmm... But why use them then? Why don't our Aegeans stick with the soft stones they have in their areas and are easy to engrave?
Well, there are various reasons to prefer them to soft stones... First of all, hard stones have lustrous surfaces and a more luscious look than soft stones. Just a look at this translucent amethyst and this, in comparison, dull-looking green serpentine proves the point! Which is more impressive?
A, ok, yes this makes sense...
Plus, do not forget that seals are made to be worn on the body and are often be used to stamp on clay! So, while the hardness of hard stone seals means their surface is not that easily worn from use, the soft surface of soft stones gets easily abraded. This means the seal will become unusable after a while! Look at this steatite seal, its surface is so worn out from use you can hardly make out the motif!
I understand, yes... But tell me, how do you define a stone as soft or hard?
Look here, this is Moh's scale of mineral hardness. Here you have various minerals categorised by their hardness on a scale from 1 to 10, where 1 is the softest and 10 is the hardest mineral. A mineral can always be scratched by one that is harder than it is, whereas the opposite is not possible. The soft stones in Aegean glyptic range in hardness from Mohs 2-4 and the hard ones from Mohs 5-8. Stones of hardness Mohs 4-5 are medium hard, that is they can just, and with a lot of effort, be engraved by hand tools!
Ok, I understand... But one last thing... We do not only have stone seals, I remember we also have bone seals, those made of animal's tusk, gold, glass...
Yes, of course... Bone and animal tusk, including hippo ivory, but also gold and other metals are soft materials. This means they can be engraved with hand tools! Glass, on the other hand, when available in its final state, as a solid raw material, I mean, is a hard material!
Ok, I understand... So this means we have soft materials that can be engraved by hand tools and hard materials that, because of their hardness, require another technique for engraving!
Yes... But I am coming to the techniques next time, after Christmas, ok? Merry Christmas to you Fritz!
Thank you! Merry Christmas, Genius!!!