COLLECTION OF CAVE PEARLS - Golconda Mine, Derbyshire (ex. R.J.King collection)

(ex. R.J.King collection. Collected in the early 1960s from a collapsed adit while researching the geology of Golconda Mine - see below)

A cave pearl is a small pebble that usually forms by the accumulation of calcium carbonate around a nucleus. They occur on the floors of caves and mines where water is flowing too vigorously to form a stalagmite. 

Like stalactites and stalagmites, cave pearls take a long time to form and nowadays cavers are advised not collect them but to leave them in place for others to see.

Reference: Ford, T.D. and King, R.J., 1965. Layered epigenetic galena- barite deposits in the Golconda Mine, Brassington, Derbyshire, England. Economic Geology, 60, 1686-1701.