What kind of rock

Asked August 12, 2019, 1:36 AM EDT

A friend brought me a rock he found about the size of a basket ball that he broke open . Inside is it is filled with air pockets that have crystals and some place have what looks like a white shell she if you crack them open they are filled with black crystals. Can anyone give me a clue?

Outside United States geology

1 Response

The rock appears to be volcanic because those amazing crystals are filling air pockets. Mineral rich waters flow through volcanic rocks after the initial deposition. The minerals that precipitate out are usually quartz. These appear to be a diverse variety of other minerals like zeolites. The fine "hairs" on the orange balls are indicative of zeolite crystal habits. I suggest you take your rock to a local geologist for further identification. https://en.wikipedia.org/wiki/Zeolite

These minerals are very fragile, as you've probably already observed. They are fun to look at with a loupe or a magnifying glass.
Nice rock!!!