Ultramafic rock but there are ultrapotassic and highly silica-under-saturated rocks with >18% MgO which can be considered "ultramafic". Ultrapotassic, ultramafic igneous rocks such as lamprophyre, lamproite and kimberlite are known to have reached the surface of the Earth. Although no modern eruptions have been observed, analogues are preserved. Most of these rocks occur as dikes, diatremes, lopoliths or laccoliths, and very rarely, intrusions. Most kimberlite and lamproite occurrences occur as volcanic and subvolcanic diatremes and maars; lavas are virtually unknown. Vents of Proterozoic lamproite (Argyle diamond mine), and Cenozoic lamproite (Gaussberg, Antarctica) are known, as are vents of Devonian lamprophyre (Scotland). Kimberlite
Gemstone Healer Gemstone Healer Gemstone Healer is a computer action adventure game created by Canadian developer Paradigm Creators and published in 1986 by Strategic Simulations. It was developed by Trouba Gossen (who was also responsible for the graphics), Peter Lount (design and programming); with assistance by Kevin Pickell (porting to C-64). It is a sequel to "Gemstone Warrior". "Gemstone Healer" is a 2D action adventure title with the player controlling an armored figure that they would move from area to area in search of treasure and the way to heal the Gemstone. It uses cellular automata to generate maps. The game takes