AMETHYST
Specimen ame-45
$ 410.00Dims: 13.5" x 8.4" x 5.0" (34.3 x 21.3 x 12.7 cm)
Wt: 19.9 lbs. (9.1 kg)
Minas Gerais, Brazil
One of the largest specimens in our present stock, this behemoth consists of a large geode that formed from an air bubble in a lava flow whose interior was coated with a crust of hundreds of Amethyst crystals. The crystals occur in the hexagonal prismatic form with pyramidal terminations that are the only parts that are exposed and visible. There is a small amount of visible damage to some of them, but the vast majority are in excellent condition, with clean faces and edges. When the geode was harvested, a hole was drilled through the skin so that its contents could be determined before money and time were invested in sawing it up. This hole has been plugged up, and the job was done pretty well, in comparison to similar geodes that I have seen. The plug is visible from the geode's exterior, where one can see a difference in the lava skin's texture. The crystals on the interior reach maximum dimensions of a bit over 1" (2.5 cm) long by 1" (2.5 cm) in diameter. They all have a vitreous luster, and are transparent, with a moderately pale violet color at their tips. However, they cloud up and their color fades towards the bases of their terminations. Some of the crystals contain inclusions that are black to brown in color, and sometimes have a silky luster. These inclusions are made up of cacoxenite, an iron aluminum phosphate hydroxide that is often found trapped in Brazilian Amethyst crystals. Among the Amethysts are a large cluster of prismatic calcite crystals and some smaller, more massive deposits. All are white and have a pearly luster- a few Amethyst crystals are coated with a sparkly crust of calcite. There is a very thin layer (2-3 mm thick) of pale gray agate between the Amethyst druse and the green lava skin. One end of the geode has been cut flat and bolstered with concrete to form a base so that it can stand upright, and there are cork feet on this base to protect whatever surface on which it is placed. It is a truly splendid piece!
Wt: 19.9 lbs. (9.1 kg)