This specimen of bastite serpentine is from Kynance cove in Cornwall. Serpentinite is a coarse grained rock composed of one or more of the serpentine minerals. Heat and pressure was applied to peridotite as it moved upwards from the moho, the resulting metamorphic process creating serpentinite. The primary serpentine mineral at Kynance cove is bastite sepentine, the other being tremolite.