I had to research a bit for this cool green Rock. Obviously the colour indicates that it has something to do with copper. It was in an old crystal collection, inside a bag marked "Azureite and Malachite". It is neither.

It has a green streak, it is extremely lightweight, and it is crumbly. I deduced that it is chrysocholla but I could still be wrong.

It's bright green and feels almost like green pumice. It hasn't been washed because it is a little fragile. I will make sure the rock hound (Cassy) leaves me some bubble wrap to pack it with.