NASA's Curiosity rover has made a groundbreaking discovery on Mars by uncovering pure sulfur crystals within a broken rock.

MacEwan, D. M. C., Bull. 169, Calif. Div. of Mines, p. 78. “X-Ray Diffraction by Polycrystalline Materials”, Chap. 5, p. 145 (Inst. Phys., London, 1955). Beevers ...

Together, they make the substance, calcium phosphate. Sidewalk chalk is made from calcium and sulfate, which makes calcium sulfate. One of the most common chemicals connected to calcium is called ...