DR JEREMY BURGESS / SCIENCE PHOTO LIBRARY DR JEREMY BURGESS / SCIENCE PHOTO LIBRARY
Scanning electron micrograph of fur from a domestic kettle, showing the crystals that form in a hard water area (Norwich, Norfolk). The fur consists of crystals of calcium carbonate (pebbles, not seen here) & crystals of calcium sulphate (needles). Hardness is caused by calcium salts; calcium bicarbonate (temporary) & calcium sulphate (permanent). When water containing calcium bicarbonate is boiled, the soluable bicarbonate breaks down to give the insoluable calcium carbonate. When water containing calcium sulphate is evaporated, boiled or dries out, the calcium sulphate percipitates out of solution. Mag:X1600 (at 10x8 size).
Model release not required. Property release not required.