spar n.  Min. An old name for a nonmetallic mineral, usually cleavable and somewhat lustrous; as, calc spar, or calcite, fluor spar, etc.  It was especially used in the case of the gangue minerals of a metalliferous vein.
 Blue spar, Cube spar, etc. See under Blue, Cube, etc.

 ◄ ►


 Cube n.
 1. Geom. A regular solid body, with six equal square sides.
 2. Math. The product obtained by taking a number or quantity three times as a factor; as, 4x4=16, and 16x4=64, the cube of 4.
 Cube ore Min., pharmacosiderite. It commonly crystallizes in cubes of a green color.
 Cube root. Math., the number or quantity which, multiplied into itself, and then into the product, produces the given cube; thus, 3 is the cube root of 27, for 3x3x3 = 27.
 Cube spar Min., anhydrite; anhydrous calcium sulphate.