Search results
Results from the WOW.Com Content Network
An amethyst geode that formed when large crystals grew in open spaces inside the rock. The largest amethyst geode found as of 2007 was the Empress of Uruguay, found in Artigas, Uruguay in 2007. It stands at a height of 3.27 meters, lies open along its length, and weighs 2.5 tons. Amethyst is also found and mined in South Korea. [19]
When the mineral is observed at some angle, light following some combination of paths and polarizations will be present, each of which will have had light of different colors absorbed. At another angle, the light passing through the crystal will be composed of another combination of light paths and polarizations, each with their own color.
Peridot is one of the few gemstones that occur in only one color: an olive-green. The intensity and tint of the green, however, depends on the percentage of iron in the crystal structure, so the color of individual peridot gems can vary from yellow, to olive, to brownish-green. In rare cases, peridot may have a medium-dark toned, pure green ...
It is a mixture of amethyst and citrine with zones of purple and yellow or orange. Almost all commercially available ametrine is mined in Bolivia. The colour of the zones visible within ametrine are due to differing oxidation states of iron within the crystal. The citrine segments have oxidized iron while the amethyst segments are unoxidized.
Lazurite is a deep‐blue to greenish‐blue. The colour is due to the presence of S − 3 anions. [8] It has a Mohs hardness of 5.0 to 5.5 and a specific gravity of 2.4. It is translucent with a refractive index of 1.50. It is fusible at 3.5 on Wolfgang Franz von Kobell's fusibility scale, and soluble in HCl.
Prasiolite (also known as green quartz, green amethyst or vermarine) is a green variety of quartz. Since 1950, almost all natural prasiolite has come from a small Brazilian mine, [citation needed] but it has also been mined in the Lower Silesia region of Poland. Naturally occurring prasiolite has also been found in the Thunder Bay area of ...
Charoite (/ tʃ æ r oʊ. aɪ t / CHAR-ow-ait) is a rare silicate mineral with the chemical composition K(Ca,Na) 2 Si 4 O 10 (OH,F)•H 2 O, first described in 1978.It is named after the Chara River, despite its being 70 kilometres (43 mi) away from the discovery place.
Fabrics dyed in the current era from different species of sea snail. The colours in this photograph may not represent them precisely. Tyrian purple (Ancient Greek: πορφύρα porphúra; Latin: purpura), also known as royal purple, imperial purple, or imperial dye, is a reddish-purple natural dye.