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Color index is a geological term, an indicator of the types of minerals present, and the specific type of rock. The color index of an igneous rock is...

Geology (from Ancient Greek γῆ (gê) 'earth', and λoγία (-logía) 'study of, discourse') is a branch of natural science concerned with the Earth and other...

characteristic, along with its characteristic blue color. Its name comes from the same origin as that of the color cyan, being derived from the Ancient Greek...

Epstein, J., Harris, L. (1977). "Conodont Color Alteration - an Index to Organic Metamorphism." United States Geological Survey Professional Paper 995, 1-27...

Planetary geology, alternatively known as astrogeology or exogeology, is a planetary science discipline concerned with the geology of celestial bodies...

The refractive index, as well as the specific gravity, vary slightly depending on the iron concentration; a dominant cause of peridot color variation. The...

Quartz Index (QI): D11*D11 / D10*D12 Mafic Index (MI): D12/D13 Surficial soil is a good proxy to the geology underneath. Some of the properties of soil...

rocks with a high proportion of pyroxene and olivine, so that their color index (the volume fraction of dark mafic minerals) is between 50 and 90. Most...

marketed by the jewelry industry because of its emerald-like color, good refractive index, although its durability is low. It has a hardness of just 5...

Pennsylvania." Geological Survey Research (1972): D29-D36. Harris, Anita G. "Conodont color alteration, an organo-mineral metamorphic index, and its application...

sufficient trace elements to produce color centers. Color in this red or pink series is annealed in geological conditions above temperatures of around...

hydrangeas. White hydrangeas cannot be color-manipulated by soil pH because they do not produce pigment for color. In other words, while the hue of the...

Cinnabar has a mean refractive index near 3.2, a hardness between 2.0 and 2.5, and a specific gravity of approximately 8.1. The color and properties derive from...

: 19  The gem gets its red color from manganese ions embedded inside of beryllium aluminium cyclosilicate crystals. The color of red beryl is stable up...

transparent fluorite has anomalous partial dispersion, that is, its refractive index varies with the wavelength of light in a manner that differs from that of...

This glossary of geology is a list of definitions of terms and concepts relevant to geology, its sub-disciplines, and related fields. For other terms related...

Index (VEI) Alert Level was raised to 2 (on a scale of 1–4) on 2 May 2010. Level 1 is "Normal" and Level 2 is "Advisory" with an Aviation Alert color...

the silica mineral chalcedony colored by impurities of iron oxide. The color can vary greatly, ranging from pale orange to an intense almost-black coloration...

are characterized in terms of their color (hue, tone and saturation), optical phenomena, luster, refractive index, birefringence, dispersion, specific...

variety of the beryl family, with its name relating to water and sea. The color of aquamarine can be changed by heat, with a goal to enhance its physical...