Strange new rocks come into our store.

We recently had some folks bring in a crate of obsidian they were looking to sell. After quickly looking over the crate, we came to an agreement on price and made the deal. I assumed it was all obsidian so I didn't go through it right away. Then one of my regulars came in to buy obsidian. I allowed him to go through the crate while I tended to customers. After a while he came to me with these five rocks asking what kind of obsidian they were.

Right away, I knew they weren't obsidian. It was at this point the mystery began. First I cleaned all the calcite off them and looked carefully at each piece.
Each one has a strange crystal cleavage structure.

The crystals even have red fire in them which I couldn't get to show well in the pics.

One even has a crystal sticking out the side.


I had a friend, who is a crystologist, check them out. He couldn't be certain, but believes the red crystals are a form of braciated garnet. However, that is at best, an educated guess.
The black matrix also has similar cleavage on a smaller scale.

If anyone has an idea what they are, please share.