noun
definition
A soft, glassy form of gypsum (chemical formula CaSO4·2H2O).
definition
The anion SeO32− derived from selenous acid; any salt or ester of selenous acid.
Examples of selenite in a Sentence
It consists mainly of grey dreary flats covered with selenite; and a little below the surface, gypsum.
Meyer (Ber., 1902, 35, p. 1 59 1) by the electrolysis of silver selenite in the presence of potassium cyanide obtained the value 79.22.
Such plates are generally made of mica or selenite, and the normal to the plane of polarization of the most retarded stream is called "the axis of the plate."
In fact, the lateral systems are obtained when a plate of selenite is substituted for the quartz.
Below the analyser G a plate H of selenite or mica may be put in the course of the rays.
Pete arranged some photographs of the passage profile and the selenite crystals on the mud floor.
Viewing is greatly improved by the " blue " selenite slip.
In the following year he discovered the change, produced by change of temperature, in the direction of the optic axes of selenite.
Manufacturers are expected to replace organic selenium with sodium selenite.
Calcium sulphate, CaSO 4, constitutes the minerals anhydrite (q.v.), and, in the hydrated form, selenite, gypsum (q.v.), alabaster (q.v.), and also the adhesive plaster of Paris (see Cement).
In this part of its course the rocky sides of the valley, which sometimes closely approach the river, are composed of marls and gypsum, with occasional selenite, overlaid with sandstone, with a topping of breccia or conglomerate, and rise at places to a height of 200 ft.
The mineral was probably included with selenite under Pliny's term lapis specularis.
Thus the sulphate constitutes the minerals anhydrite, alabaster, gypsum, and selenite; the carbonate occurs dissolved in most natural waters and as the minerals chalk, marble, calcite, aragonite; also in the double carbonates such as dolomite, bromlite, barytocalcite; the fluoride as fluorspar; the fluophosphate constitutes the mineral apatite; while all the more important mineral silicates contain a proportion of this element.
Children can be given supplements containing 1.0 mg sodium selenite.