出典:Wikipedia
出典:『Wikipedia』 (2011/05/22 13:22 UTC 版)
Rose rocks are aggregates of barite (barium sulfate) crystals and sand whose iron content gives them a reddish hue. The barite crystals form a circular array of flat plates, giving the rock a shape similar to a rose blossom. Rose rocks appear either as a single rose-like bloom or as clusters of blooms, with sizes ranging from pea sized to four inches (20 cm) in diameter. The rose rock was selected as the official state rock of Oklahoma in 1968.