Pumice stone is one of the natural ingredients employed by the apothecaries and doctors of old. Pumex or Lapis Pumicis is a porous volcanic rock with low density and light color. It was sometimes called, erroneously, Sea foam (in fact sepiolite). Basaltic scoria is another vitreous volcanic stone, dark in color, denser and with larger vesicles, used more rarely in apothecary context.
Pumice powder was used as ingredient (mechanical abrasive cleaning agent) in tooth powders (dentifrices), in medicine against ulcers (of the skin and cornea) and as scar removal. The entire stone was sometimes employed by pharmacists as a kind of file, to scrape other materials. Together with other ingredients (antimony, distilled water, walnut shells etc.) it was boiled into concoctions for diet (Decoctum Lusitanicum) or urinary problems.
The History of Pharmacy Collection in Cluj presents the ingredient in its FOCUS display for the month of October 2016. The tematic display includes actual pumice and scoria stones and one 19th-century wooden jar from the “Unicorn” Pharmacy in Cluj, with the signature Pulv. Pumicis Lap. As the Latin abbreviated inscription indicates, the jar was used for the storage of powdered pumice stone. Another relevant objects in the collection is a valuable 17th century closet from the Officina, once used in the “Black Eagle” Pharmacy in Sibiu. One of its drawers of the is also inscribed Lap. Pumicis. (pumice stone). More recent still, a similar inscription - Pulv. Lap. Pumic. - is to be found on a 20th century closet from the Hintz Pharmacy which houses the museum.