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Monazite is an important ore for thorium, [8] lanthanum, and cerium. [9] It is often found in placer deposits. India, Madagascar, and South Africa have large deposits of monazite sands. The deposits in India are particularly rich in monazite. Monazite is radioactive due to the presence of thorium and
Poikiloderma vasculare atrophicans, or PVA, indicates that extra or altered skin pigmentation ("poikiloderma") [10] is occurring, associated with heightened visibity of capillaries ("vasculare", referring to telangiectasia) under the skin, related to thinning and wasting away ("atrophicans") of the skin and its tissue. Telangiectasia is an ...
Defatting is the chemical dissolving of dermal lipids, from the skin, on contact with defatting agents. This can result in water loss from the affected area and cause the whitening and drying of the skin which may result in cracking, secondary infection and chemical irritant contact dermatitis. [1]
It is the cerium-dominant analogue of monazite-(La), monazite-(Nd), and monazite-(Sm). It is also the phosphorus analogue of gasparite-(Ce). [ 3 ] The group contains simple rare earth phosphate minerals with the general formula of AXO 4 , where A = Ce, La, Nd, or Sm (or, rarely, Bi), and X = P or, rarely, As.
Fissure is a lesion in the skin that is usually narrow but deep. [29] [33] Induration is dermal thickening causing the cutaneous surface to feel thicker and firmer. [29] Atrophy refers to a loss of skin, and can be epidermal, dermal, or subcutaneous. [30] With epidermal atrophy, the skin appears thin, translucent, and wrinkled. [29]
Xenotime is a rare-earth phosphate mineral, the major component of which is yttrium orthophosphate (Y P O 4).It forms a solid solution series with chernovite-(Y) (Y As O 4) and therefore may contain trace impurities of arsenic, as well as silicon dioxide and calcium.
In such cases, a thin section of the mineral is used and examined under polarized transmitted light with a petrographic microscope. Another device using this property to identify minerals is the dichroscope .
In optical mineralogy and petrography, a thin section (or petrographic thin section) is a thin slice of a rock or mineral sample, prepared in a laboratory, for use with a polarizing petrographic microscope, electron microscope and electron microprobe. A thin sliver of rock is cut from the sample with a diamond saw and ground