Name/Title
Salammoniac After OrthoclaseEntry/Object ID
2009.62.140Description
Chemical Composition: NH4CL
Crystal System: Cubic or Isometric S
Description: Common Name: Sal Ammoniac
Chemistry: NH4Cl, Ammonium Chloride
Class: Halides
Location: Unknown
Description: Opaque, porus and angular, cream colored with some slight specks of reflective mineral throughout the specimen.
PHYSICAL CHARACTERISTICS:
Color is colorless, white or off-white almost yellow.
Luster is vitreous.
Transparency: Crystals are transparent to translucent.
Crystal System: Isometric; possibly of the gyroidal class 4 3 2.
Crystal Habits include cubes, octahedrons and dodecahedrons. Complicated arborescent, snowflake-like and dendritic specimens are available. Crusts and coatings are more common.
Cleavage is poor in one direction.
Fracture is conchoidal to earthy.
Hardness is 1.5 - 2
Specific Gravity is 1.5 (very light).
Streak is white.
Associated Minerals include sodium alum, sulfur and other fumarole minerals.
Best Field Indicators are crystal habit, associations, origin of formation, softness and density.
Fracture: Conchoidal
Hardness: 1 Talc
Luster: Glassy
Occurrence: Sal ammoniac forms on volcanic rocks near fume releasing vents. There is no liquid phase as the mineral crystallizes from these fumes in a process called sublimation. The crystallization occurs as the gases are escaping and crystals tend to be short-lived. Sal ammoniac is very soluble in water and crystals will be removed during the first rain of their existence, so to speak, if they are not removed by collectors first.
Rock Type: Igneous
Specific Gravity: 1.5
Streak: white
Variety: It is commonly used as a flux in the soldering of stained-glass windows. In both 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 (0.75% copper) or karated gold. Anything other than 24-karat gold has silver and copper added. Usually the addition of silica, zinc, and deoxidants in very small amounts relative to the pennyweight (dwt.) of gold are processed into gold from as low as 8-karat to as high as 23.5-karat gold. This is added to prevent porosity or cracking while milling the ingot further into wire, sheet, or tubing. Without those additives an otherwise poor-quality ingot will result in open crucible melting with a hand torch or blowpipe and flame, as was done before electric melting furnaces were invented for use in the precious metals industry. These practices are still used by metalsmiths and jewelers today.
Sal ammoniac has also been used in the past in bakery products to give cookies a very crisp texture, although that application is rapidly dying due to the general disuse of it as an ingredient. However, in some areas of Europe, particularly Scandinavia, it is still widely used in the production of salty licorice candy known as Salmiak or Salmiakki. In Finland, Salmiakki is dissolved in vodka to make a drink of the same name.
The term sal ammoniac has largely fallen out of general use in the 20th century.Collection
RAGM Mineral CollectionAcquisition
Accession
2009.62Source or Donor
Museum Collection of MineralsAcquisition Method
DonationLocation
Location
Display Case
FS-5-ARoom
Frieda Smith HallBuilding
Crater Rock MuseumCategory
ExhibitMoved By
Ian C.Date
January 29, 2025Notes
Major mineral groups installationCategory
PermanentMoved By
Rawley WyattDate
May 20, 2014