objects in aluminium. Olivine sand requires less water than silica sands while still holding the mold together during handling and pouring of the metal. Less water means less gas (steam) to vent from the mold as metal is poured into the mold. In Finland, olivine is marketed as an ideal rock for sauna stoves because of its comparatively high density and resistance to weathering under repeated heating and cooling. Gem-quality olivine is used as a gemstone called peridot. See also References External links Pretty Green Mineral – Pretty Dry Mars? by Linda M.V. Martel, Planetary Science Research Discoveries, Hawai'i Institute of Geophysics and Planetology Olivine Page Farlang library: Historic sources + modern articles on Olivine and Peridot Geological information and several microscopic images University of North Dakota Industrial minerals Iron(II) minerals Magnesium minerals Minerals in space group 62 Nesosilicates Orthorhombic minerals de:Olivingruppe