Nephrite Nephrite Nephrite is a variety of the calcium, magnesium, and iron-rich amphibole minerals tremolite or actinolite (aggregates of which also make up one form of asbestos). The chemical formula for nephrite is Ca(Mg, Fe)SiO(OH). It is one of two different mineral species called jade. The other mineral species known as jade is jadeite, which is a variety of pyroxene. While nephrite jade possesses mainly grays and greens (and occasionally yellows, browns or whites), jadeite jade, which is rarer, can also contain blacks, reds, pinks and violets. Nephrite jade is an ornamental stone used in carvings, beads, or cabochon cut gemstones.
Guianan cock-of-the-rock their definitive plumage at around three years. Juvenile females look almost identical to their adult counterparts. Guianan cocks-of-the-rock have a total length of approximately and a total weight of around . The two species of cock-of-the-rock are allopatric, and therefore do not meet with one another. The plumage of male Andean is redder and its wings are mostly black, lacking the orange colouration seen on the male Guianan. The female Andean is reddish brown rather than the brownish-gray of the Guianan. The Guanian cock-of-the-rock is one of two species of genus "Rupicola". It was described by Carl Linnaeus in 1766