Mineral Information and Data:

CH3CONH2 [CNMNC approved formula]

Named for ACETic acid and AMIDE, for ammonia in its composition.

IMA status : Approved Species 1974 (IMA1974-039)
(8th edition) :  
  (50) Salts of Organic Acids and Hydrocarbons
  (50.04) with miscellaneous formulae
(10th edition) :
  (10) Organic Compounds
  (10.A) Salts of Organic Acids
  (10.AA) Formates, Acetates, etc.
Crystal system: Trigonal System
Point group (H-M): 3m — ditrigonal-pyramidal
Space group: R3c
Unit cell: a = 11.44 Å, c = 13.5 Å
Crystal Habit: Crystals are prismatic, to 5 mm; as small stalactites and in granular aggregates
Color: Colorless, gray if included with carbonaceous material.
Luster: Vitreous to greasy
Hardness (Mohs): 1 - 1.5
Measured Density: 1.17 g/cm3
Fracture: Fine Conchoidal
Streak: White
Geologic Setting: Acetamide has been detected near the center of the Milky Way galaxy. This finding is potentially significant because acetamide has an amide bond, similar to the essential bond between amino acids in proteins. This finding lends support to the theory that organic molecules that can lead to life (as we know it on Earth) can form in space.
Also in burning waste coal heaps, formed between 50 °C and 150 °C.
Mineral Association: Sal ammoniac (Chervonograd, Ukraine)
Other Properties: H2O Soluble.
Comments: Taste very bitter; volatilizes on exposure to air and sunlight.


White crystalline crust of acetamide on black shale.
Origin: Shamokin, Northumberland County, Pennsylvania, USA.
Photo : Jeff Weissman / Photographic Guide to Mineral Species