"Crocidolite" Quotes from Famous Books
 ... tougher than the clear crystallized quartz. Carnelian, agate, quartz cat's-eye, jasper (containing earthy impurities), and those materials in which quartz has more or less completely replaced other substances, such as silicified crocidolite, petrified wood, chrysocolla quartz, etc., are all nearly as hard and quite as tough as quartz itself, and they make admirable stones for inexpensive rings of the ...
— A Text-Book of Precious Stones for Jewelers and the Gem-Loving Public • Frank Bertram Wade |
