2.7" Pink Amethyst Geode Section with Calcite - Argentina

This is a beautiful find out of Argentina, featuring true pink amethyst crystals from the Choique Mine. It occurs in geodic formations or cavities lined with crystals. This piece is 2.7" wide and the crystals have an excellent pink color and nice terminations. This specimen has a number of calcite crystals that formed among the amethyst.

This material has been analyzed at the California Institute of Technology and was described as "purplish pink amethystine quartz additionally coloured by microscopic hematite particles". They are not rose quartz or pink quartz as classically defined.

Pink amethyst is formed by the same processes that gives amethyst its purple color, but by definition amethyst is purple, not pink. Thus, we are left with a conundrum of what to call it! But since the majority of people seem to be calling it "pink amethyst", we will stick with that label.

Amethyst is a purple variety of quartz (SiO2) that owes its violet color to natural gamma irradiation, iron impurities, and the presence of trace elements, which result in complex crystal lattice substitutions. It is considered a semi-precious gemstone, and just two centuries ago was considered to have a value on par with diamonds, sapphires, and rubies. The largest and best known amethyst deposits occur in southern Brazil and Uruguay, where they are found in hydrothermally-formed geodes, but many localities around the world produce an amazing variety of amethyst crystals and formations. They are almost always formed in medium- to high-temperature geological settings.

Calcite, CaCO3, is a carbonate mineral and the most stable polymorph of calcium carbonate. The other polymorphs are the minerals aragonite and vaterite. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals. However, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, and prisms. Calcite exhibits several twinning types adding to the variety of observed forms. It may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form.

SOLD
DETAILS
SPECIES
Quartz var. Pink Amethyst & Calcite
LOCATION
Choique Mine, Pehuenches, Neuquen, Argentina
SIZE
2.7 x 1.8"
ITEM
#134783