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Chromite can also be presented in a thin section. The grains seen in thin sections are disseminated with crystals that are euhedral to subhedral. [12] Chromite contains Mg, ferrous iron [Fe(II)], Al and trace amounts of Ti. [5] Chromite can change into different minerals based on the amounts of each element in the mineral.
Chromitite with bronzite phenocrysts from Stillwater Igneous Complex. Chromitite is an igneous cumulate rock composed mostly of the mineral chromite.It is found in layered intrusions such as the Bushveld Igneous Complex in South Africa, the Stillwater igneous complex in Montana and the Ring of Fire discovery in Ontario.
Bushveld Igneous Complex geologic map and mine locations. The Bushveld Igneous Complex (BIC) is the largest layered igneous intrusion [1] [2] within the Earth's crust. [3] It has been tilted and eroded forming the outcrops around what appears to be the edge of a great geological basin: the Transvaal Basin.
Loveringite is found to be grayish white to gray in plane polarized light and does not display pleochroism. Additionally, when viewed in plane polarized light, Loveringite is found to have high relief and has sharp grain boundaries, shows fractures and cleavages well, and sticks out above other minerals in the thin section.
In chemistry the term chromite has been used in two contexts. Under IUPAC naming conventions, chromate(III) is preferred to chromite. [citation needed] For compounds containing an oxyanion of chromium in oxidation state of +3; For other compounds of chromium(III) as a means of distinguishing a chemical species such as hexacyanochromite(III).
Thin sections are prepared in order to investigate the optical properties of the minerals in the rock. This work is a part of petrology and helps to reveal the origin and evolution of the parent rock. A photograph of a rock in thin section is often referred to as a photomicrograph.
A bowenite cabochon featured as part of the "Our Mineral Heritage Brooch", was presented to U.S. First Lady Mrs. Lady Bird Johnson in 1967. Williamsite is an American local varietal name for antigorite that is oil-green with black crystals of chromite or magnetite often included. Somewhat resembling fine jade, williamsite is cut into cabochons ...
An ophiolite is a section of Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed, and often emplaced onto continental crustal rocks. The Greek word ὄφις, ophis (snake) is found in the name of ophiolites, because of the superficial texture of some of them. Serpentinite especially evokes a snakeskin.