"'Ye can get the powdered stones from a London apothecary,' she was saying, frowning slightly as she pushed at the sliding lid. But they're mostly poor quality, and the bhasmas doesn't work so well. Best to have a stone at least of the second quality—what they call a nagina stone. That's a goodish-sized stone that's been polished. A stone of the first quality is faceted, and unflawed for preference, but most folk canna afford to burn those to ash. The ashes of the stone are the bhasmas,' she explained, turning to look up at me. 'That's what ye use in the medicines.'"