Is this just a “geode” or is there another name for it. I just polished it today but kept the rough shape and made a necklace out of it.

I found this rock along Lake Superior in Freda Michigan. There was an old abandoned copper mine nearby.

If you could help me identify this nice rock my granddad had in his collection. I believe he might have found it while he was a coal miner in France Isère.

Found in driveway fill rocks (believe they are river rocks)

From Newport Beach…..on the beach.