I've been buying quite a bit of this stone recently. It's one of my current close friends.

Kambaba Jasper or Crocodile Jasper or Crocodile Rock is a very ancient rock from Madagascar, formed from fossilised stromatolite algae.

It is quite beautiful - dark green with grey/black swirls and circles. It has a very gentle grounding energy, is calming, sustaining and nourishing, and brings a profound sense of wellbeing.