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Phaneritic rock: Anorthosite from the Stillwater Igneous Complex (Neoarchean; Montana) Igneous textures include the rock textures occurring in igneous rocks.Igneous textures are used by geologists in determining the mode of origin of igneous rocks and are used in rock classification.
An amethyst geode that formed when large crystals grew in open spaces inside the rock. The largest amethyst geode found as of 2007 was the Empress of Uruguay, found in Artigas, Uruguay in 2007. It stands at a height of 3.27 meters, lies open along its length, and weighs 2.5 tons. Amethyst is also found and mined in South Korea. [19]
Vugs, cavities and geodes are all examples of open-space filling phenomena in hydrothermal systems. Alternatively, hydraulic fracturing may create a breccia which is filled with vein material. Such breccia vein systems may be quite extensive, and can form the shape of tabular dipping sheets, diatremes or laterally extensive mantos controlled by ...
In geology, texture or rock microstructure [1] refers to the relationship between the materials of which a rock is composed. [2] The broadest textural classes are crystalline (in which the components are intergrown and interlocking crystals), fragmental (in which there is an accumulation of fragments by some physical process), aphanitic (in which crystals are not visible to the unaided eye ...
The cavity, which measured 8.0 by 1.8 by 1.7 metres (26.2 ft × 5.9 ft × 5.6 ft), was, at the time, the largest crystal cave ever found. Following its discovery, the entrance to the cave was blocked by five tons of rock, with an additional police presence to prevent looters.
The Empress of Uruguay is the world's largest amethyst geode, standing at a height of 3.27 meters. It is open along its length and weighs 2.5 tons in its current state. It was discovered in 2007 in the Artigas department, Uruguay by the Uruguayan mining company Le Stage Minerals. Its estimated value is US $190,000, although it is not for sale. [1]
Anhedral crystal growth occurs in a competitive environment with no free space for the formation of crystal faces. An intermediate texture with some crystal face-formation is termed subhedral (also known as hypidiomorphic or hypautomorphic). Crystals that grow from cooling liquid magma typically do not form smooth faces or sharp crystal ...
In geology and mineralogy, druse is a crystal habit represented by the coating of fine crystals on a rock fracture surface, [1] or vein or within a vug or geode. [ 2 ] See also