Tumbled stone
A tumbled stone is a piece of rough mineral mechanically polished in a rotating drum with progressively finer abrasives, until it takes on a rounded shape that is smooth to the touch. It is the most common format in lithotherapy, valued for its affordable price and the ease with which it slips into a pocket or sits in the hand. Polishing changes nothing in the nature of the mineral, only its surface.
Tumbled or raw
This is the question everyone asks in the shop. Tradition draws no hierarchy: lapidaries credit a tumbled stone with the same qualities as a raw crystal, only the surface differs. A tumbled stone slips in anywhere and stands up to daily life; a raw one keeps its edges and its wild look. Choose with the hand as much as the eye, since the right stone is often the one you like to touch.
The right gesture
A tumbled stone is carried in the pocket, held in the palm for the length of a pause, set on the bedside table. Just keep its hardness in mind: a tumbled fluorite or calcite will scratch if it travels with quartz, so store them separately. And rinse it now and then under clear water if its nature allows, the way you would rinse a pebble brought home from the beach.
Sources
- , The Curious Lore of Precious Stones (1913)
- , Manual of Mineral Science (2007)