Rio Tinto | Minerals and Metals for the world

Chris Morrissey's AtoZ of metals and minerals
So, how do we wrap up the alphabet? With bunny tails, geology's popcorn, Red Riding Hood and a bit of an Oopsy...

U is for ulexite, a boron-bearing mineral with some curious habits - "habit" being the term geologists use to describe the shape and appearance that minerals take on as they crystallize. Ulexite forms colourless crystals with a glassy appearance, but quite often the crystals become aggregated together as white, silky masses that look like cotton balls and are known as "bunny tails". In another habit, ulexite masses resemble the white hearts of cauliflowers.

Ulexite, named after a German chemist who identified it in 1849, is a hydrated borate of sodium and calcium. Together with other natural borates, such as the sodium borate called either borax or tincal, it is crucially important as a source of boron and its many useful compounds. A major use is in the manufacture of heat resistant glass, especially glass fibre. Boron compounds have thousands of uses in metallurgy, agriculture and a wide variety of manufactured products, many of them everyday domestic products, such as detergents and cosmetics.

Borate deposits containing ulexite typically form by solar evaporation of saline lakes enriched with boron from local volcanic sources. The most important examples are in the US and Turkey. Smaller deposits dominated by ulexite occur in some of the Andean countries, for instance Chile and Bolivia. Rio Tinto Borax (www.borax.com) supplies nearly half the world's demand for industrial borates, chiefly from its long established open pit mine near the town of Boron in California's Mojave Desert. Ulexite is one of the main ore minerals there, and at the company's Tincalayu open pit in Argentina.



Chris Morrissey's AtoZ of metals and minerals So, how do we wrap up the alphabet? With bunny tails, geology's popcorn, Red Riding Hood and a bit of an Oopsy... U is for ulexite, a boron-bearing mineral with some curious habits - "habit" being the term geologists use to describe the shape and appearance that minerals take on as they crystallize. Ulexite forms colourless crystals with a glassy appearance, but quite often the crystals become aggregated together as white, silky masses that look like cotton balls and are known as "bunny tails". In another habit, ulexite masses resemble the white hearts of cauliflowers. Ulexite, named after a German chemist who identified it in 1849, is a hydrated borate of sodium and calcium. Together with other natural borates, such as the sodium borate called either borax or tincal, it is crucially important as a source of boron and its many useful compounds. A major use is in the manufacture of heat resistant glass, especially glass fibre. Boron compounds have thousands of uses in metallurgy, agriculture and a wide variety of manufactured products, many of them everyday domestic products, such as detergents and cosmetics. Borate deposits containing ulexite typically form by solar evaporation of saline lakes enriched with boron from local volcanic sources. The most important examples are in the US and Turkey. Smaller deposits dominated by ulexite occur in some of the Andean countries, for instance Chile and Bolivia. Rio Tinto Borax (www.borax.com) supplies nearly half the world's demand for industrial borates, chiefly from its long established open pit mine near the town of Boron in California's Mojave Desert. Ulexite is one of the main ore minerals there, and at the company's Tincalayu open pit in Argentina.
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