Wednesday, April 17, 2013

Gemstone of the Week: Cacoxenite

(Image of Cacoxenite found on
(Image of Cacoxenite in Quartz found on

Cacoxenite is an interesting looking gem.  It forms as these almost cute looking little crystal puff balls.  It is a secondary mineral and is often found in the oxidized zone of phosphatic magnetite deposits. It may also be found in phosphate-rich pegmatites, in novaculites (a form of chert or flint), and sometimes, though rarely, in soils and sediments that are rich in iron.  Cacoxenite is a hardness 3-4 and in colour may range from yellow to brownish-yellow, reddish orange, golden yellow, deep orange, and green. In transmitted light it appears yellow.  It is a translucent gemstone with a silky luster.  Cacoxenite was discovered in 1825 and it's name comes from the Greek words meaning 'bad' and 'guest.'  A rather unusual name to give a a gem, but the reason for it was because of how if there was Cacoxenite present in ore for iron smelting the phosphorus content of the Cacoxenite lessened the quality of the smelting. Cacoxenite, it would appear, is frequently found in/with various types of Quartz as a great many of the images I have seen of it involve Cacoxenite inside of regular Quartz or even Amethyst the result of which is absolutely stunning. Cacoxenite is found in: Australia, Austria, Belgium, Brazil, Bulgaria, Cameroon, Canada (province of Ontario), Czech Republic, France, Germany, Hungary, Ireland, Italy, Japan, Mexico, Namibia, Portugal, Romania, Rwanda, Slovakia, Spain, Sweden, England, Wales, Uruguay, and in the states of: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Florida, Georgia, Missouri, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Pennsylvania, South Carolina, South Dakota, Tennessee, Virginia, and Wisconsin.