Is obsidian recorded in ancient books?

Crow bloodstone should not be obsidian. I have been struggling with the difference between the two, but from a chemical point of view, crow's bloodstone is pure SiO _ 2, which means it is crystalline, while obsidian is 70%-75% SiO _ 2, MgO and Fe3O4.

Hardness (crow 7, obsidian 5.6),

Refractive index (Wuliang 1.54- 1.55, Obsidian 1.48- 1.5 1)

The specific gravity (crow 2.65, obsidian 2.35) is also different.

According to the online introduction, the obsidian in Wujin is extremely delicate, so it has no cat's eye effect, and its color is as bright and black as crow's blood stone. That is to say, it is very close to the crow's blood stone, but the real black-gold obsidian is gem-grade obsidian, which is much rarer than all kinds of cat's eye obsidian, so it is more precious and valuable, so I personally think that some people say that obsidian without rainbow eyes is inferior, and it is not necessarily accurate to pretend to be crow's blood stone. Whether there is a rainbow or a cat's eye is not the only criterion to judge obsidian, so there is no problem that crow bloodstone is a defective product without rainbow eyes, let alone that crow bloodstone is a defective product without rainbow eyes.