Most common mafic minerals in ultramafic rocks are definitely pyroxenes and olivine (if hornblende is present it is added to pyroxenes). Properties of rock is another aspect for Dunite vs Peridotite. Learn more about Peridotite vs Dunite in the next section. Nearest village is Åheim and genetically associated is dunite which is mined at Gusdal quarry. Properties of rock is another aspect for Peridotite vs Dunite. Chromite is a principal ore of chromium. It is a typical ternary plot which are often used in geology. These include lherzolite, harzburgite, dunite, wehrlite, and kimberlite (see photos). Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Le Maitre, R. W. (2005). For Ni, a simple Nernst-type partition coefficient was used: \[ D_{\rm Ni}^{\rm Ol/lq} = {C_{\rm Ni}^{\rm Ol} \over C_{\rm Ni}^{\rm lq}} = 10. Peridotite vs Dunite characteristics assist us to distinguish and recognize rocks. Fresh dunite is used in parts of glass furnaces. Closer view of a pyroxenite layer in pyrope-bearing dunite. This rock is relatively rare at the surface and is often altered by hydrothermal metamorphism or weathering because its constituent minerals are unstable at the weathering environment. Most of them have an obvious green color, attributed to their olivine content. Width of sample 9 cm. Massive samples are often brought to the surface as xenoliths inside basalt. Replacive dunite is a product of the reaction between a pyroxene-bearing host rock and an olivine-saturated magma, which dissolves orthopyroxene in the host peridotite and sometimes crystallizes olivine. I live in Cyprus and I have collected many periodite rocks just trying to understand Geology step by step . The specific heat capacity of Peridotite is 1.26 kJ/Kg K and that of Dunite is 1.25 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Peridotite is heat resistant, pressure resistant, wear resistant whereas Dunite is heat resistant, pressure resistant, wear resistant. 1. Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. Peridotite is available in dark greenish - grey colors whereas, Dunite is available in dark greenish - grey colors. The process of formation of rocks is different for various rocks. Layered ultramafic typically occur at the base of gabbroic intrusions. Lherzolite is the least pretentious of them — it is a mixture of two pyroxenes and olivine1. I have collected them from Troodos as well as 3 km from Limassol beach , they are different in that the Troodos ones are layered and the Limassol ones are more large grained crystal & what i thought is called Pyroxenite or hornblendite … i can’t tell . They are further divided into subtypes. It can be formed in two ways. Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. Hullvann, Norway. Wehrlite (clinopyroxene peridotite) from Norway. Dunite: a peridotite that is composed mainly of olivine and may contain significant amounts of chromite, pyroxene, and spinel. Fresh dunite is used in parts of glass furnaces. Nickel and platinum are usually associated with ultramafic host rocks. Åheim, Norway. The interior uses of Dunite include Decorative aggregates and Interior decoration whereas the interior uses of Peridotite include Decorative aggregates and Interior decoration. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Peridotite is available in dark greenish - grey colors whereas, Dunite is available in dark greenish - grey colors. How to read this diagram? GSA Bulletin ; 81 (8): 2181–2202. You can check out Dunite vs Peridotite information and Dunite vs Peridotite characteristics in the upcoming sections. It is one of the main host rocks of talc deposits and platinum metals and formerly was a major source of magnesite. \], \[ K_{\rm Al}^{\rm Opx} = {C_{\rm MF}^{\rm Sp} \over C_{\rm MF}^{\rm Ol}} \cdot {\left(C_{\rm Fe}^{\rm lq} K_{\rm MF}^{\rm Ol} + C_{\rm Mg}^{\rm lq} \right) \over \left(C_{\rm Fe}^{\rm lq} K_{\rm MF}^{\rm Sp} + C_{\rm Mg}^{\rm lq} \right)} \cdot {(C_{\rm Al}^{\rm Sp})^{2} \over C_{\rm Al}^{\rm Opx(M1)}} = 5. The intrusion, which is one of the largest of all the British Palaeogene plutonic/volcanic centres, contains a range of coarse-grained igneous rock types including gabbros, dunites, peridotites and allivalites, some of which display igneous layering indicating that this is an exhumed magma chamber. The streak of Peridotite and Dunite is white. Deformation experiments on dunite and peridotite, both in the presence and absence of externally released H 2 O, have been carried out in solid pressure media apparatus in the confining pressure range 5 to 30 kb, temperature interval 300°C to 1400°C at constant strain rates ranging from 10 −3 to 10 −8 /sec. They are further divided into subtypes. Also you can check about Properties of Peridotite and Properties of Dunite. Preliminary mechanical results indicate that steady state deformation takes place only in the temperature-strain rate range in which the diffusion controlled processes of polygonization and recrystallization are important or dominant. They are quickly altered by hydrothermal solutions and weathering. Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. Cambridge University Press. Peridotite vs Dunite characteristics assist us to distinguish and recognize rocks. Should be easy to find. Layered peridotite is a cumulate rock formed by crystal settling from magma. You can also check out the list of all Igneous Rocks. Peridotites can be formed in two ways: as mantle rocks formed during the accretion and differentiation of the Earth or as cumulate rocks formed by precipitation of olivine and pyroxenes from basaltic magmas. Wehrlite contains almost no orthopyroxene but is rich in clinopyroxene and olivine. Search for other works by this author on: This content is PDF only.