Salammoniac

Salammoniac, also sal ammoniac or salmiac, is a rare naturally occurring mineral composed of ammonium chloride, NH4Cl. It forms colorless, white, or yellow-brown crystals in the isometric-hexoctahedral class. It has very poor cleavage and is brittle to conchoidal fracture. It is quite soft, with a Mohs hardness of 1.5 to 2, and it has a low specific gravity of 1.5. It is water-soluble. Sal ammoniac is also the archaic name for the chemical compound ammonium chloride. Ammonium chloride#Applications It is commonly used to clean the soldering iron in the soldering of stained-glass windows. In jewellery-making and the refining of precious metals, potassium carbonate is added to gold and silver in a borax-coated crucible to purify iron or steel filings that may have contaminated the scrap. It is then air-cooled and remelted with a one-to-one mixture of powdered charcoal and sal ammoniac to yield a sturdy ingot of the respective metal or alloy in the case of sterling silver (7.5% copper) or karated gold. Sal ammoniac has also been used in the past in bakery products to give cookies or biscuits their crisp texture, but the application of food grade baking ammonia (ammonium carbonate or (NH4)2CO3) is generally being substituted with the creation of modern baking powder or baking soda (sodium bicarbonate). Sal ammoniac is used in salmiac liquorice, for instance salty liquorice or salmiak pastilles. In addition, the mineral or, better, its synthetic counterpart, also serves for the production of cooling baths as well as in dyeing and leather tanning. Sal ammoniac (ammonium chloride) was the electrolyte in Leclanché cells, a forerunner of the dry battery; a carbon rod and a zinc rod or cylinder formed the electrodes. It was also brought into pharmacopeias by Islamic physicians for medicinal purposes.