>>474687Yes they are still in use and with modern technologies coming up they might become more common.
so the only thing its really good for is cutting, but in that category its one of the world fucking
best.so its starts to have a comeback as medical equipment. since its around 100x sharper then a standard stainless steel scalpel.
>why?(long boring text inc)
obsidean knifes go down to the molecule level since are made by fracture of amorph material not by grinding.
Steel is almost always composed of very many separate crystals (alloys improve steel by filling the gaps between crystals), rather than one large one.
When steel fractures, it typically fractures along the uneven joins between separate crystals.
Obsidian contains almost no crystals large enough to affect the material's fracture properties and it is for this reason it breaks smoothly and sharply.
Because obsidian lacks crystals, it does not break along lines of weakness in the material, it just fractures along the lines of the stress that caused the fracture. (This is also why obsidian and similar materials show conchoidal fractures.)
When you look at the shape of some fractured obsidian, you are looking at the shape of the shockwave that cracked it (
>>474703 this is why i suspect that wood is not used so often)
. When you look at the shape of some fractured steel, you are looking partly at the shape of the shockwave that fractured it, but mostly at the lines of weakness between the steel's imperfections and the joins between it's crystals. This effect is enhanced by the grinding of the sharpening process and causes the "saw" like cutting edge.
(pic related)
