Volcanic pipe Volcanic pipe Volcanic pipes are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes. They are considered to be a type of "diatreme". Volcanic pipes are composed of a deep, narrow cone of solidified magma (described as "carrot-shaped"), and are usually largely composed of one of two characteristic rock types — kimberlite or lamproite. These rocks reflect the composition of the volcanoes' deep magma sources, where the Earth is rich in magnesium. Volcanic pipes are relatively rare. They are well known as the primary source of diamonds, and are mined for this purpose. Volcanic pipes form as
GemStone IV GemStone IV GemStone IV is a multiplayer text-based online role-playing video game (often known as a MUD) produced by Simutronics. Players control characters in a High Fantasy game world named "Elanthia". The first playable version of the game was known as "GemStone ][" and was launched in April 1988 on GEnie. It was one of the first MMORPGs and is one of the longest running online games still active. Access to the game is subscription-based (monthly fee) through its website, with three additional subscriptions levels available, "Premium," "Platinum," and "Shattered", in addition to a free-to-play model introduced in early March,