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 (database) e-commerce web pages or in web application frameworks such as the Seaside web framework. Systems based on object databases are not as common as those based on ORM or object-relational mapping frameworks such as TopLink or Hibernate. In the application framework market, JBoss and BEA Weblogic are somewhat analogous to GemStone. Gemstone (database) GemStone/S is computer software, an application framework that was first available for the programming language Smalltalk as an object database. It is proprietary commercial software. GemStone Systems was founded on March 1, 1982 as Servio Logic, to build a database machine based on a set theory model.