Jeremejevite is an

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

borate mineral The Borate Minerals are minerals which contain a borate anion group. The borate (BO3) units may be polymerised similar to the SiO4 unit of the silicate mineral class. This results in B2O5, B3O6, B2O4 anions as well as more complex structures whic ...

with variable

fluoride Fluoride (). According to this source, is a possible pronunciation in British English. is an Inorganic chemistry, inorganic, Monatomic ion, monatomic Ion#Anions and cations, anion of fluorine, with the chemical formula (also written ), whose ...

and

hydroxide Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It ...

ions. Its

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

is . It is considered as one of the rarest, thus one of the most expensive stones. For nearly a century, it was considered as one of the rarest gemstones in the world. It was first described in 1883''Damour A.'' Note sur un borate d'alumine cristallisé de la Siberie. Nouvelle espèce minerale // Bulletin de la Société minéralogique de France. 1883. 6. N 1. P. 20-23. as small, single crystals in loose granitic debris in Mt. Soktui, Nerschinsk district, Adun-Chilon Mountains,

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

. It was named after Pavel Vladimirovich Eremeev, Russian mineralogist, engineer and professor, who collected the first specimens (Jeremejev, German; 1830–1899).

Properties

Jeremejevite is a mineral that shows pleochroic properties, which is an

optical phenomenon Optical phenomena are any observable events that result from the interaction of light and matter. All optical phenomena coincide with quantum phenomena. Common optical phenomena are often due to the interaction of light from the Sun or Moon with ...

in which the mineral's color appears to change depending on the angle at which it is viewed. Blue specimens from Namibia show a light

cornflower blue Cornflower blue is a shade of medium-to-light blue containing relatively little green. This hue was one of the favorites of the Dutch painter Johannes Vermeer. The most valuable blue sapphires are called cornflower blue, having a medium-da ...

to colorless to light yellow pleochroism, while yellow materials show light yellow to colorless pleochroism. This mineral is also

piezoelectric Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied stress (mechanics), mechanical s ...

, meaning that it would generate electricity when under mechanical stress.

Mining and localities

Jeremejevite occurs as a late

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

phase in

granitic A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental ...

pegmatites A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic com ...

in association with

albite Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. It represents a plagioclase with less than 10% anorthite content. The pure albite endmember has the formula . It is a tectosilicat ...

tourmaline Tourmaline ( ) is a crystalline silicate mineral, silicate mineral group in which boron is chemical compound, compounded with chemical element, elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. This gemstone comes in a ...

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

and rarely

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate Hydrate, dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk ...

. It has also been reported in the

Pamir Mountains The Pamir Mountains are a Mountain range, range of mountains between Central Asia and South Asia. They are located at a junction with other notable mountains, namely the Tian Shan, Karakoram, Kunlun Mountains, Kunlun, Hindu Kush and the Himalaya ...

Tajikistan Tajikistan, officially the Republic of Tajikistan, is a landlocked country in Central Asia. Dushanbe is the capital city, capital and most populous city. Tajikistan borders Afghanistan to the Afghanistan–Tajikistan border, south, Uzbekistan to ...

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

and in micro-crystalline form at the Eifel district,

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

. It was first found in facetable form in Namibia, which were blue-green pyramidal crystals up to . Later, there was a new source revealed in Namibia, near Usakos in 2001. Nowadays, most of the stones on the market are from that deposit.

Jewelry industry

As an OH-end member, scientists have been able to synthesize jeremejevite, but only in micro-crystalline form, without fluorine. This synthesized variant of the mineral has no use in the jewelry industry. Typically, faceted gems can reach up to 5 carats, but usually they range between less than 1 carat and 2 carats. However, new sources produced much larger faceted stones, the biggest faceted gem weighing 254 carats. This gem was found in Sri Lanka in 1990. Even though jeremejevite is a relatively durable stone, it should not be cleaned using ultrasound cleaning or steaming; the stone usually contains liquid inclusions, which could shatter the stone if cleaned using these methods. It is recommended to clean them with warm water, a mild detergent, and a soft brush instead. Due to its high value and rarity, it is considered a collectors' stone, who purchase it in mineral form, hence only a few specimens had been faceted so far.

References

Borate minerals Hexagonal minerals Minerals in space group 176 {{mineral-stub