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.
Tensor product of quadratic forms Tensor product of quadratic forms The tensor product of quadratic forms is most easily understood when one views the quadratic forms as "quadratic spaces". If "R" is a commutative ring where "2" is invertible, and if formula_1 and formula_2 are two quadratic spaces over "R", then their tensor product formula_3 is the quadratic space whose underlying "R"-module is the tensor product formula_4 of "R"-modules and whose quadratic form is the quadratic form associated to the tensor product of the bilinear forms associated to formula_5 and formula_6. In particular, the form formula_7 satisfies (which does uniquely characterize it however). It follow