Black Tourmaline Quartz Tumbled Crystal

Among the books, decks, and stones on 14th Street is this tumbled stone: Black Tourmaline Quartz Tumbled Crystal (shop SKU LTQT2).

Black tourmaline, or schorl, is an iron-rich tourmaline, typically opaque and striated. In crystal traditions, it is associated with protection and grounding. Those ideas belong to folklore and personal practice, not to any medical claim.

Tumbled stones are polished in a drum, which softens sharp edges and brings out color. Natural stones vary in color, clarity, and shape, so the piece you receive will have its own character even when the weight, grade, or size is listed.

• SKU: LTQT2

Find it at Namaste Bookshop, 2 West 14th Street, a short walk from Union Square in Manhattan, or order it online.