Portuguese for “hollow,” Oco Geodes are found in the steep hills of Tres Pinheiros in the state of Rio Grande do Sul, Brazil. Ocos can range in size from one inch up to five or six inches in diameter. Quartz crystals commonly line the inside of these spectacular geodes, and rarely the crystals are amethyst. Many of the Ocos contain black needle-like crystals (probably goethite) among the quartz. Ocos are easily distinguished by their “rope-like” surface on both the inside and outside of the geode. When cut and polished, the rims display prominent white wavy or flame-like patterns similar to their Trancas geode cousins.
One of the many members of the quartz family, amethyst gets its beautiful purple hue due to traces of iron. Deriving its name from the ancient Greek amethustos, amethyst literally translates as “not drunk” and was once believed to protect one against drunkenness. Many religions around the world have at one time or still do consider amethyst helpful in bringing one to a higher spiritual state and thus closer to god. Amethyst today is still used for spirituality and is considered the #1 addiction recovery stone. Amethyst is found in abundance in Brazil, Africa, Uruguay, Mexico, Canada, and the U.S.A.