A silver-gilt mounted rock crystal pendant,

of spherical form originally worn on a belt to protect the wearer from evil spirits,
rock crystal was also believed to detect poison in and impart healing powers
to any liquid it was placed in. Drinks the stone had been dipped in
would be drunk by or sprinkled on those who required aid.

Similar examples such as charmstone of the Stewarts of Ardsheal were
prized by the families that owned them and were lent to those who
needed their protection.

Scottish, circa 1590.

Literature:

R.K. Marshall and G.R. Dalgleish (ed), The Art of Jewellery in Scotland, 1991.

A similar rock crystal ball, dating to the sixth century, is in the collection
of the British Museum.

This piece is currently being exhibited in
'Faith and Fortune: Five Centuries of European Masterworks'
at the Wadsworth Atheneum Museum of Art, Connecticut.

Diameter 4.2 cm