serpentiniitit
Serpentiniitit are a group of minerals that form when peridotite, an ultramafic igneous rock, is hydrated and altered by water circulating through the Earth's crust. This process, known as serpentinization, typically occurs at low temperatures and pressures, often associated with tectonic plate boundaries. The primary minerals found in serpentinite are serpentine group minerals, which are hydrous magnesium iron silicates. These include antigorite, chrysotile, and lizardite.
The appearance of serpentinite can vary widely, ranging from dull green to almost black, and it can
Serpentinite formations are often found in ophiolites, which are fragments of oceanic crust and upper mantle