Calcite is one of the most ubiquitous minerals, being an important rock forming mineral in sedimentary environments. It is an essential component of limestones, and occurs in other sedimentary rocks. It also occurs in metamorphic and igneous rocks, and is common in hydrothermal environments.

A variety of minerals contribute to the composition of lava rocks. The most common minerals are pyroxine, olivine, amphibole and plagioclase feldspar, although low quantities of hornblende, biotite mica, magnetite and quartz are occasionally present.

Volcanic rocks are named according to both their chemical composition and texture. Basalt is a very common volcanic rock with low silica content. Rhyolite is a volcanic rock with high silica content. Rhyolite has silica content similar to that of granite while basalt is compositionally equal to gabbro.

Calcite is not a common mineral in igneous rocks, but it may occur in alkali-rich (high Na- and K-content) rocks containing feldspathoids like nepheline or sodalite. Carbonatite is a rare and still somewhat mysterious igneous rock that is usually composed mostly of calcite.

It can be useful to put a piece of Blue Calcite near to any areas where a thief may choose to gain access to your home or business. This lovely crystal resonates quite strongly within both the third eye chakra and the throat chakra.

Calcite is more stable in general than aragonite, although as temperatures and pressures change one of the two minerals may convert to the other. At surface conditions, aragonite spontaneously turns into calcite over geologic time, but at higher pressures aragonite, the denser of the two, is the preferred structure.

Calcium carbonate can take the form of two different minerals: Calcite is the stable form, whereas aragonite is metastable: Over time, or when heated, it can ultimately transform into calcite. Calcium carbonate usually crystallizes as calcite, but surprisingly, it forms aragonite in seawater.

Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, CaCO3 (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including precipitation from marine and freshwater environments.

Over 800 forms of calcite crystals have been identified. Most common are scalenohedra, with faces in the hexagonal {2 1 1} directions (morphological unit cell) or {2 1 4} directions (structural unit cell); and rhombohedral, with faces in the {1 0 1} or {1 0 4} directions (the most common cleavage plane).

The cleavage of calcite is usually in three directions parallel to the rhombohedron form. Calcite is also very soft compared to the steel of a rock hammer, so breaks easily.

Calcite is barely soluble in water. The influence of temperature on solubility is low. However, if water contains CO2, the solubility of calcite increases considerably because of the formation of carbonic acid that will react forming soluble calcium bicarbonate, Ca(HCO3)2.

Physical properties Calcite is number 3 on the Mohs hardness scale; thus, it can be scratched readily by a knife blade or geologic pick. It has a specific gravity of 2.71. Three perfect cleavages give calcite its six-sided polyhedrons with diamond-shaped faces; the angles defining the faces are 78° and 102°.

That means the hardness of gold is between gypsum and calcite. So the hardness of gold is about 2.5 on the scale. A hardness of 2.5 means that gold is a relatively soft mineral. It is only about as hard as your fingernail….Mohs Hardness Scale.

Gold in association with calcite was frequently found at the Red Ledge mine in Nevada County, Ca.

Mining for gold may conjure mental images of shiny nuggets rounded by their trips down streams. But gold can also grow into stunning crystals as it emerges from naturally heated, mineral-rich waters flowing through rocky crevices. When these crystals are elongated, they’re often called wires.

Quartz has a massive crystalline appearance and can be white, yellow, pink, purple, grey or black. Gold occurs in between the other crystals found in quartz.

Silver wire: A specimen of wire silver with a heavy tarnish of acanthite on a calcite matrix. Specimen is approximately 6 x 4 x 3 centimeters in size….

Silver can be found across many geographies, but about 57% of the world’s silver production comes from the Americas, with Mexico and Peru supplying 40%. Outside of the Americas, China, Russia, and Australia combine to make up nearly 22% of the world’s production.

Warren Buffett does not invest in gold. He has invested almost $1 billion in silver, so the reason for his aversion is not simply a dislike for precious metals. Silver has a myriad of industrial and medical uses.

The lowest rates in continental Europe are in Switzerland, where VAT on silver is 8%. At today’s prices, that will add about $1.50 to each one-ounce silver coin… a little less than the low premium over spot you’d pay to an online dealer in the US, or from our friends in Singapore where your silver is stored for free.