Mexican Jalisco Rainbow Obsidian Rough Chunk Lapidary Stone Magnetite Sandstone due to nearly the same

due to nearly the same chemical composition

but you can see that it does carry some of the wood grain

These are perfect for tumbling or trimming

however it is perfectly stable as it is

Blue Chalcedony

Mexican Jalisco Rainbow Obsidian Rough Chunk Lapidary Stone Magnetite Sandstone due to nearly the sameMexican Rainbow Obsidian is also known as Jalisco Obsidian. It tends to be a pretty pure form of Obsidian, with high flash and bright colors. Typical chunks of Jalisco Obsidian normally have only one color of flash, though under rare circumstances, there can be multiple colors present. Unlike Velvet Obsidian, the magnetite in Rainbow Obsidian generally only flows in one direction, which creates the effect you see. Rainbow Obsidian does only flash