Arctite ( Na₂ Ca₄( P O₄)₃ F) is a colourless mineral found in the

Kola Peninsula sjd, Куэлнэгк нёа̄ррк , image_name= Kola peninsula.png , image_caption= Kola Peninsula as a part of Murmansk Oblast , image_size= 300px , image_alt= , map_image= Murmansk in Russia.svg , map_caption = Location of Murmansk Oblast ...

northern

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...

.Mineral Handbook
/ref> Its IMA

symbol A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different conc ...

is Arc. It has a Mohs hardness of 5 and has a

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water (molecule), wa ...

of 3.13. Arctite is

transparent Transparency, transparence or transparent most often refer to: * Transparency (optics), the physical property of allowing the transmission of light through a material They may also refer to: Literal uses * Transparency (photography), a still, ...

with a vitreous lustre. Arctite has a perfect cleavage and a

trigonal In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal ...

crystal system In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices. Space groups are classified into crystal systems according to their poi ...

. It is also a naturally occurring

antiperovskite Antiperovskites (or inverse perovskites) is a type of crystal structure similar to the perovskite structure that is common in nature. The key difference is that the positions of the cation and anion constituents are reversed in the unit cell s ...

.Arctite Supergroup on Mindat
/ref> Common associates of arctite include

aegirine Aegirine is a member of the clinopyroxene group of inosilicate minerals. Aegirine is the sodium endmember of the aegirine-augite series. Aegirine has the chemical formula Na Fe Si2 O6 in which the iron is present as Fe3+. In the aegirine-augite ...

, natisite,

lomonosovite Lomonosovite is a phosphate–silicate mineral with the idealized formula Na10Ti4(Si2O7)2(PO4)2O4 early Na5Ti2(Si2O7)(PO4)O2 or Na2Ti2Si2O9*Na3PO4. The main admixtures are niobium (up to 11.8% Nb2O5), manganese (up to 4.5 %MnO) and iron (up t ...

umbite Umbite (chemical formula ) is a potassium zirconosilicate mineral found in northern Russia. Named after Lake Umb ( Lake Umbozero), its type locality is Vuonnemiok River Valley, Khibiny Massif The Khibiny Mountains (russian: Хиби́ны ; sjd ...

and thenardite.

References

Webmineral data
Phosphate minerals Trigonal minerals Minerals in space group 166 {{phosphate-mineral-stub