Serpentine is a green coloured schist rock, most famous from its type locality along the Lizard peninsula, Cornwall. These specimens come from the Isle of Anglesey, have a much more vibrant colour and are available in various sizes.
Serpentinite is a rock composed of one or more serpentine group minerals, hydrous magnesium iron phyllosilicates, it is also well known as a source of asbestos, although in this natural rock form, it posses absolutely no threat at all. Minerals in this group are formed by serpentinization, a hydration and metamorphic transformation of ultramafic rock from the Earth's mantle. The mineral alteration is particularly important at the sea floor at tectonic plate boundaries. The rock derives it's name from the greenish & sometimes scaly or waxy appearance reminiscent of a serpent. Serpentines found along the Lizard Peninsula in Cornwall are locally known as Lizard rock due to their green colour, they make ideal decorative stones. These particular examples are from Anglesey which are much more greener than the Cornish variety and are supplied in labelled card trays, with options of different sizes.