Map of index minerals of the Barrovian metamorphic zones of Scotland
An index mineral is used in geology to determine the degree of metamorphism a rock has experienced. Depending on the original composition of and the pressure and temperature experienced by the protolith (parent rock), chemical reactions between minerals in the solid state produce new minerals. When an index mineral is found in a metamorphosed rock, it indicates the minimum pressure and temperature the protolith must have achieved in order for that mineral to form. The higher the pressure and temperature in which the rock formed, the higher the grade of the rock.
The concept traces its roots to 1912, when G. M. Barrow mapped zones of metamorphism in Scotland. Each zone is named for the index mineral that appears in it, for example, the chlorite zone is named for chlorite.
An indexmineral is used in geology to determine the degree of metamorphism a rock has experienced. Depending on the original composition of and the pressure...
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific...
characteristic indexmineral of the zone. Whether a certain indexmineral occurs is also dependent on the composition of the rock itself. Many indexminerals have...
and it is an important indexmineral used by geologists to trace metamorphic zones. Kyanite is an aluminum silicate mineral, with the chemical formula...
The Mineral Wells Index was a daily newspaper published in Mineral Wells, Texas, on weekday afternoons and Sunday mornings. The Index coverage area included...
Every metamorphic facies has some indexminerals by which it can be recognized. That does not mean these minerals will necessarily be visible with the...
Thus, as with its other polymorphs, andalusite is an aluminosilicate indexmineral, providing clues to depth and pressures involved in producing the host...
sillimanite are common in metamorphosed sedimentary rocks. It is an indexmineral indicating high temperature but variable pressure. Example rocks include...
nesosilicate mineral, and more specifically, an aluminosilicate mineral. It is one of the hardest naturally occurring minerals and has a relatively low index of...
Garnets ( /ˈɡɑːrnɪt/) are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess...
metamorphism. These minerals are known as indexminerals. Examples include sillimanite, kyanite, staurolite, andalusite, and some garnet. Other minerals, such as...
conditions for an indexmineral (a mineral that indicates the approximate metamorphic grade of a rock), were appropriate for these minerals to form. Buchan...
Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit...
The Mohs scale of mineral hardness (/moʊz/) is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of minerals through the ability...
manganese oxide mineral Wells A.F. (1984) Structural inorganic chemistry 5th edition Oxford Science Publications, ISBN 0-19-855370-6. This set index article lists...
refractive index of any mineral. Its mean refractive index is 3.08 (sodium light wavelengths), versus the indices for diamond and the non-mineral gallium(III)...
is a significant metamorphic mineral as it can be used as an indexmineral for high pressure conditions. Indexminerals are used in geology to determine...
Retrieved 2015-08-16. Swenson, Jim (November 10, 2009). "Refractive Index of Minerals". Newton BBS / Argonne National Laboratory. US DOE. Archived from...
systems. Zircon is one of the key minerals used by geologists for geochronology. Zircon is a part of the ZTR index to classify highly-weathered sediments...
Hard water is water that has a high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone...
3 common minerals found in ultra-weathered sediments: zircon, tourmaline, and rutile. Other minerals that can be used alongside the ZTR index are garnet...
Global Information