GeologyRocks

Hi Everyone,

I was wondering if you could help me figure out what this rock is...Found on Angel Island --Ayala Cove

It kind of looks like a miniture stump, and not a rock much. Also, there are a variation of colors like spoted whites, brown, some black on the ends, and very little red and the rock is not a solid. There are layers, similar to mica sheets, but the lines are not cleavage, instead are fractured. The rock is fine-grained and visible with the naked eye. I do notice some sparking in the rock as well. I used white vinegar to test fizzing, but there was no reaction. Adding on, I used my finger-nail to try scratching, but the rock is slightly stronger. However, when I used a knife-blade, the knife-blade was stronger than the rock. I filled my sink with water, but the rock is not dense (or heavy) enough to float to the top. I just learned that the rock smells like wet mudd when wet..

Thank You Very Much!!!