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English: Exhibit in the Natural History Museum of Utah, Salt Lake City, Utah, USA. This item is old enough so that it is in the public domain. Photography was permitted in the museum without restriction.
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO 3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed ...
Boxwork in Wind Cave, South Dakota. In geology, boxwork is defined as a honeycomb-like structure that can form in some fractured or jointed sedimentary rocks. If the fractures in the host rock are mineralized, they can become more resistant to weathering than the surrounding rock, and subsequent erosion can produce boxwork structures.
Tabulata, commonly known as tabulate corals, are an order of extinct forms of coral.They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defined by a skeleton of calcite, similar in appearance to a honeycomb.
Honeycomb in the "supers" that are not used for brood (e.g. by the placement of a queen excluder) stays light-colored. Numerous wasps , especially Polistinae and Vespinae , construct hexagonal prism-packed combs made of paper instead of wax; in some species (such as Brachygastra mellifica ), honey is stored in the nest, thus technically forming ...
Barytocalcite often forms oriented growths on baryte, and calcite, witherite and baryte can be epitaxial on barytocalcite. [ 3 ] [ 4 ] Crystals are normally short to long prismatic and striated. They are transparent to translucent, colourless, white, greyish, greenish or yellowish with a white streak and a vitreous to resinous lustre .
The minerals that accompany them are calcite, epidote, vesuvianite, garnet, wollastonite, diopside and amphibole. The scapolites are colorless, flesh-colored, grey or greenish; occasionally they are nearly black from the presence of very small enclosures of graphitic material.
It is a metasomatic rock with a microscopic or very-fine grain size produced by hydrothermal alteration of basalt, and composed of albite or oligoclase, together with chlorite, epidote, calcite, and actinolite. [3] Spilite is veined by calcite or chalcedony, and vesicles and cavities are filled with secondary minerals. [2]