Birch Mountains kimberlite field shales interbedded with kimberlite at some of the diatremes are consistent with a Late Cretaceous age (Late Albian to Maastrichtian). The volcanic rocks of the BM field consist primarily of crater-facies pyroclastic kimberlite and resedimented kimberlite. They include massive layers, as well as bedded and graded layers of coarse lapilli alternating with layers of finer tuff. Lapilli and olivine phenocrysts are set in a grey-green matrix of serpentine, carbonate minerals (calcite, dolomite and magnesite) and clay minerals. Phlogopite, oxide minerals (ilmenite, perovskite and spinel), apatite and pyrite are also present. Diamonds and microdiamonds have been recovered from samples taken from
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.