CHALCOPYRITE GALENA SPECIMEN
A beautiful Chalcopyrite Galena Specimen. Super cute and collectable, specimens like this are quite fascinating. Interesting Crystal forms with partial Octocubes of Galena and a splash of Sphalerite on the back.The Sphalerite has some good Crystal formations with slight transparency. A great mineral specimen for the beginner or advanced collector.
6.1cm x 7.7cm x 4.5cm, 300g.
Galena is a common and popular mineral for rock hounds. Its characteristic cubes, distinctive cleavage and high density make it easy to identify. The structure of Galena is identical to that of halite, NaCl. The two minerals have the same crystal shapes, symmetry and cleavage. Some Galena may contain up to 20% silver in place of lead.
One of the first transistors was a Galena Crystal and with a copper wire called “cats-whisker-with crystal”. Galena is a natural semiconductor. Really it formed part of a transistor, a more reliable PN junction or Diode. Metal Sulfides form natural PN Junctions like copper and copper oxide which also formed one of the first solar panels. Such an interesting subject I could on on about it.
Galena is the primary ore mineral of lead and and ore of Silver. Worked for its lead content as early as 3000 BC. Found in ore veins with sphalerite, pyrite, chalcopyrite, tennantite-tetrahedrite and skarns. Also found in sedimentary rocks where it replaces carbonate beds or deposites in pore spaces. The crystals are bright when fresh but often tarnish when people touch them. Lead sulfide may contain impurities, such as silver, arsenic, antimony, and copper.
Named in 1725 by Johann Friedrich Henckel from the Greek “chalkos”, copper, and “pyrites”, strike fire.
A major ore of copper. Common in sulfide veins and disseminated in igneous rocks. Weathering may lead to the formation of malachite, azurite, brochantite, langite and numerous other secondary copper minerals.
Sphalerite also known as Blende or Zinc Blende is the major ore of zinc. When pure with little or no iron it forms clear crystals with colours ranging from pale yellow (Cleiophane) to orange and red shades (Ruby Blende). As the iron content increases it forms dark, opaque metallic crystals of Marmatite.