Bromlite, also known as Alstonite is a member of the aragonite group of minerals. It consists of an isomorphous mixture of calcium and barium carbonates in various proportions, (Ca,Ba) C0₃, and thus differs chemically from barytocalcite, which is a double salt of these carbonates in equal molecular proportions. Being isomorphous with aragonite, it crystallizes in the orthorhombic system, but simple crystals are not known. The crystals are invariably complex twins, and have the form of doubly terminated pseudo-hexagonal pyramids, like those of witherite but more acute; the faces are horizontally striated and are divided down their center by a twin suture. Categories: Carbonate minerals | Mineral stubs ... Minerals are natural compounds formed through geological processes. ... General Name, Symbol, Number calcium, Ca, 20 Series alkaline earth metal Group, Period, Block 2 (IIA), 4, s Density, Hardness 1550 kg/m3, 1. ... Barium is also the Latin name for the city Bari in Italy. ... Carbonate is an anion with a charge of -2 and an empirical formula of CO32-. An aqueous solution of carbon dioxide contains a minute amount of H2CO3, called carbonic acid, which dissociates to form hydrogen ions and carbonate ions. ... In chemistry, salt is a general term used for ionic compounds composed of positively charged cations and negatively charged anions, so that the product is neutral and without a net charge. ... Barium carbonate (BaCO3), also known as witherite, is a chemical compound used in rat poison, bricks, and cement. ...

The examination in polarized light of a transverse section shows that each compound crystal is built up of six differently orientated individuals arranged in twelve segments. Quartz crystal A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ...

The crystals are translucent and white, sometimes with a shade of pink. Specific gravity is 3.706, and hardness is 4 - 4.1. The mineral has been found at only two localities, both of which are in the north of England. At the Fallowfield lead mine, near Hexham in Northumberland, it is associated with witherite; and at Bromley Hill, near Alston in Cumberland, it occurs in veins with galena. The species was named bromlite by T. Thomson in 1837, and alstonite by A. Breithaupt in 1841, both of which names, derived from the locality, have been in common use. Relative density (also known as specific gravity) is a measure of the density of a material. ... Royal motto: Dieu et mon droit (French: God and my right) Englands location within the UK Official language English de facto Capital London de facto Largest city London Area  - Total Ranked 1st UK 130,395 km² Population  - Total (2001)  - Density Ranked 1st UK 49,138,831 377/km² Ethnicity... General Name, Symbol, Number Lead, Pb, 82 Chemical series Poor metals Group, Period, Block 14(IVA), 6 , p Density, Hardness 11340 kg/m3, 1. ... For other places with this name, see Northumberland (disambiguation) Northumberland is a ceremonial and administrative county in northern England. ... Cumberland is one of the 39 traditional counties of England. ... Galena is a lead ore. ...

This article incorporates text from the public domain 1911 Encyclopædia Britannica. The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... The Eleventh Edition of the Encyclopædia Britannica (1911) in many ways represents the sum of knowledge at the beginning of the 20th century. ...