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 Warrior Gemstone Warrior Gemstone Warrior is an action role-playing game written by Canadian developer Paradigm Creators for the Apple II and published by Strategic Simulations in 1984. It is an action-adventure title set against a 2D screen with the player controlling an armored figure that they would move from area to area in search of treasure and the pieces of the stolen Gemstone. "Gemstone Wariror" was SSI's first game to sell over 50,000 copies in North America. The game was ported to the Commodore 64, Atari 8-bit family, and Macintosh. In addition, the games were ported to the N7 Japanese system.