 In terms of working stones like these, how would say working with lapis differ from working with rock crystal or garnet? I mean I would assume that a lot of it has to do with the crystalline structure and not hitting the wrong thing at the wrong time. Well I think hitting I think you're using kind of figuratively because you're not hitting the way marble you're hitting with the hammer and chisel you're cutting, even something like porphyry you're hitting and you're chipping away. In this case more it's sort of drilling away. It's drilling or even grinding. You're grinding you're using abrasives and it's although you have tools and cutting tools the tools are carrying an abrasive which is emery which is quartz it's basically sand that you're grinding away you're abrading the stone And so it has to do with the structure of the material and lapis lazuli has a less fine structure and people talk about again a mineralogist would probably object to talk about the grain of a stone But it's a coarser stone it holds detail less well that's why it tends to be used in antiquity more decorative than used for carving. Intaglios and cameos of lapis exist but far more common is cornelian and even something amethyst calisthenia even rock crystal which are their finer stones they hold detail more you can cut them more sharply And so they tend to be used more for carving. Garnet is harder I think most of the gemstones your amethyst your rock crystal your calisthenia your jaspers there's somewhere around seven on the most scale. And Garnet I believe is eight sapphires nine and diamond is ten and that's a relative scale and an absolute scale. Diamond is is much much more is much much harder than the other stones it's not just one notch above right but and lapis I think is a little softer but it's more that it's grainy it also also has a lot of inclusions. Gold specs and that makes it harder to carve the gold is soft and it's coarser and then each of these stones often has within it especially if it's a banded stone. We'll have sort of different patches of hardness through it I guess it's if you have a kind of salami. Yeah it's got you know the meat bits and the fat bits if you're really paying attention you could cut more easily or not through different parts of the salami if you didn't have a sharp knife. So something that is you know seems to be a pure rock crystal or a pure amethyst is going to you can work it in a more uniform way. Abandoned agate might have crystalline places and their number of ancient agate works that seem to have cavities that have been removed. They haven't been filled but they're pitted where it seems that the ancient craftsman has removed the more sugary larger crystalline parts because they'll fracture and fray and get to the finer parts that are in a sense smoother and take a polish better. And that gives us a good sense looking backwards it's often hard with these works that are so highly finished to find the traces of craftsmanship. That's where a really good microscope helps and also perhaps less highly skilled workmanship will leave more traces of craft than something that's really polished the way through. The journeyman or apprentice level work for example. Or the backside of something, the underside of something that would have been attached to the mount and you can often see the traces of different tools there, the different cutting tools, the wheels, the cones, the balls, the drills, the hollow drills that leave distinctive kinds of cuts in the stone. But when they're being polished those working traces often get erased.