Saganite

Saganite, also known as "needle stone", "love stone", or "hairstone", was a variety of chalcedony with numerous straight, needle-like inclusions of a different color (usually ivory or yellow with brown or greenish black needles).

Description
The needles of these ornamental stones were often radiate, star-like, from a common center. Saganite occurred in large deposits and was often sold in fist-sized (or larger) chunks. In Amn, one may have heard two tradesmen discussing the sale price of a "fist of saganite". While non-magical, these stones responded well to enchantments. A typical stone had a base value of 10 gp.