Harold, Edmund. Focus on crystals / [electronic resource] / Edmund Harold ; crystal illustrations by Ray Skibinski.. — 1st Ballantine Books ed.. — New York : : Ballantine Books,, 1987, c1986.. — vi, 188 p. : : ill. ; 18 cm. Bibliography: p. 185. ISBN: 0345345843 (pbk.) : $3.95 9780345345844 (pbk.) Subjects--Topical Terms: Quartz crystals--Miscellanea.Occultism.Healing--Miscellanea. LC Class. No.: BF1442.Q35 / H37 1987x Dewey Class. No.: 133