Strontianite (SrCO3) is a mineral consisting of strontium carbonate. This mineral is white, greenish, or yellowish in color,
usually occurring in fibrous massive forms, but sometimes in prismatic[?]crystals.
... as "either of those element(s) of the field whose square equals b2 - 4ac". In some fields, some elements have no square roots and some have two; only zero has just one ...