SPHALERITE GALENA MINERAL SPECIMEN
An incredible SPHALERITE GALENA MINERAL SPECIMEN with Micro Quartz Crystals matrix. Many terminated crystals clustered together make for an oresome collectable piece. This specimen would grace any collection and is from one of the premier locations for this mineral. A super piece, hard to capture in pics. The Galena Crystals have formed partial Cubic shape with the corners missing forming a Cuboctahedron or Octacube. Crystals inside the crevice look amazing under a loop.
12cm x 11.3cm x 4cm, 430g.
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 (known as Cleiophane) to orange and red shades (known as Ruby Blende), but as iron content increases it forms dark, opaque metallic crystals (known as Marmatite).
Galena is a common and popular mineral for rock hounds. Its characteristic cubes, distinctive cleavage and high density make it easy to identify and a favorite in high school geology labs. 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. The large volume of Galena that is processed for lead produces enough Silver as a by product to make Galena the leading ore of Silver.
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 were experimented with in the late 1800s and early 1900s as they form natural PN Junctions like copper and copper oxide (Verde or Patina) which also formed one of the first solar panels. Such an interesting subject I could on on about it.