Stones of healing, as they used to be called, may not have been quite such fakes as skeptical moderns think.
Precious stones were prepared medicinally by, first, powdering; that is, by grinding; second, calcination, by fire or corrosion: third, purification; fourth, liquidation; fifth, distillation or volatilization—that is, dissolved in spirits of wine and distilled; sixth, sirupization, solution mixed with citron, barberries, sugar and water.
Powder of emeralds in doses of thirty to forty grains was considered an astringent. It stanched the flow of blood and strengthened the eyes. Powdered topaz and rosewater prevented bleeding and was good for digestion; it was sold by apothecaries as an antidote to madness, and, taken in time, cured asthma and induced sleep.
Powder of rubies was usually taken in doses of thirty to forty grains "to strengthen the vitals and restore lost strength!" and also prevented infection. Sapphires are highly electric; there was powder of sapphire and oil of sapphire; some "prepare a sapphire -- with cordial water, others dissolve the fine dust of a sapphire in pure vinegar and juice of lemons and give the solution with some other cordial." Powder of sapphire healed boils and sores and was also good for the eyes. Pearls were given in consumption, cured quartan ague, strengthened the nerves. "Sah of pearl" was much thought of by Paracelsus; pearls were sometimes taken in doses of six grains in water "or dissolved in vinegar, barberry juice or lemons."
Poison was the terror of the Middle Ages; it is natural, therefore, to find many remedies among gems—the jacinth, the sapphire, the diamond, the cornelian,
the ruby, the agate, the toadstone, the bezoar stone, were all used as antidotes to poison.
The Lee Penny was a famous stone of healing set in a coin brought back from the Crusades by one of the Lockarts of Lee; it was especially used in cattle diseases. The coin, attached to a chain, was dipped in a bucket of water—"three dips and a swirl," as the country people expressed it—and the water was given to the cattle. In the reign of Charles I, the Laird of Lee lent the penny to the inhabitants of Newcastle, where the plague was raging, receiving as pledge $30,000.