Acetamide
A valid IMA mineral species
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About Acetamide
Formula:
CH3CONH2
Colour:
Colourless, grey
Lustre:
Vitreous, Greasy
Hardness:
1 - 1½
Crystal System:
Trigonal
Name:
Named for the chemical compound it represents: Acetic acid amide. Acetamide is the common short name (trivial name) of this compound.
Naturally occurring acetamide (acetic acid amide).
Unique Identifiers
Mindat ID:
13
Long-form identifier:
mindat:1:1:13:6
IMA Classification of Acetamide
Approved
Approval year:
1974
Classification of Acetamide
10.AA.20
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
A : Formates, Acetates, etc.
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
A : Formates, Acetates, etc.
50.4.7.1
50 : ORGANIC COMPOUNDS
4 : Miscellaneous
50 : ORGANIC COMPOUNDS
4 : Miscellaneous
32.11
32 : Hydrocarbons, Resins and other Organic Compounds
32 : Hydrocarbons, Resins and other Organic Compounds
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ace | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Acetamide
Vitreous, Greasy
Colour:
Colourless, grey
Comment:
grey if included with carbonaceous material
Streak:
White
Hardness:
1 - 1½ on Mohs scale
Fracture:
Conchoidal
Optical Data of Acetamide
Type:
Uniaxial (-)
RI values:
nω = 1.495 nε = 1.46
Max. Birefringence:
δ = 0.035
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Chemistry of Acetamide
Mindat Formula:
CH3CONH2
Element Weights:
Elements listed:
Crystallography of Acetamide
Crystal System:
Trigonal
Class (H-M):
3m - Ditrigonal Pyramidal
Space Group:
R3c
Cell Parameters:
a = 11.44 Å, c = 13.5 Å
Ratio:
a:c = 1 : 1.18
Unit Cell V:
1,530.09 ų (Calculated from Unit Cell)
Z:
18
Morphology:
Crystals are prismatic, to 5 mm, with prominent {1120}; as small stalactites and in granular aggregates.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0009394 | Acetamide | Denne W A, Small R W H (1971) A refinement of the structure of rhombohedral acetamide Acta Crystallographica B27 1094-1098 |  | 1971 | synthetic | 0 | 293 |
| 0019020 | Acetamide | Jeffrey G A, Ruble J R, McMullan R K, DeFrees D J, Binkley J S, Pople J A (1980) Neutron diffraction at 23 K and ab initio molecular-orbital studies of molecular structure of acetamide Acta Crystallographica B36 2292-2299 | | 1980 | synthetic | 0 | 23 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.7 Å | (100) |
| 3.98 Å | (90) |
| 3.83 Å | (10) |
| 3.54 Å | (90) |
| 3.32 Å | (30) |
| 2.86 Å | (80) |
| 2.17 Å | (10) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 54 : Coal and other mine fire minerals (see also #51 and #56) |
Geological Setting:
In burning waste coal heaps, formed between 50 degrees C and 150 degrees C. Also at At Shamokin, near Burnside, Northumberland Co., Pennsylvania, USA.
Type Occurrence of Acetamide
Place of Conservation of Type Material:
Mining Museum, St. Petersburg Mining Institute, St. Petersberg, Russia;
A.E.Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia
A.E.Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia
Geological Setting of Type Material:
In waste piles of a coal shaft. A seasonal mineral, appearing only in periods of dry weather.
Synonyms of Acetamide
Other Language Names for Acetamide
Related Minerals - Strunz-mindat Grouping
| 10.AA. | Henrysunite | Na2(C2H3O3)2(H2O) |
| 10.AA.05 | Formicaite | Ca(HCOO)2 |
| 10.AA.10 | Dashkovaite | Mg(HCOO)2 · 2H2O |
| 10.AA.25 | Calclacite | Ca(CH3COO)Cl · 5H2O |
| 10.AA.30 | Paceite | CaCu(CH3COO)4 · 6H2O |
| 10.AA.35 | Hoganite | Cu(CH3COO)2 · H2O |
| 10.AA.40 | Lianbinite | (NH4)(C2H3O3)(C2H4O3) |
| 10.AA.40 | Domitrovicite | Zn(C2H3O3)2 · 2H2O |
| 10.AA.40 | Puschridgeite | Mn(C2H3O3)2(H2O)2 |
| 10.AA.40 | Lazaraskeite | Cu(C2H3O3)2 |
| 10.AA.40 | Glecklerite | Na(C2H3O3) |
| 10.AA.40 | Jimkrieghite | Ca(C2H3O3)2 |
| 10.AA.40 | Stanevansite | Mg(C2H3O3)2 · 2H2O |
| 10.AA.40 | Rasmussenite | Ca(C2H3O3)2 · 3H2O |
| 10.AA.45 | Marchettiite | C5H7N5O3 |
Other Information
Notes:
Melting point: 81°C
Boiling point: 221°C (at 1.013 bar)
Acetamide is readily soluble in water (solubility: 2 g/ml at ambient temperature). Taste very bitter; volatilises on exposure to air and sunlight.
Decomposes to ammonium acetate in contact with acids or alkali.
Boiling point: 221°C (at 1.013 bar)
Acetamide is readily soluble in water (solubility: 2 g/ml at ambient temperature). Taste very bitter; volatilises on exposure to air and sunlight.
Decomposes to ammonium acetate in contact with acids or alkali.
Health Risks:
Acetamide is classified as a potentially carcinogenic substance. It also is a mild irritant.
Industrial Uses:
In the past, acetamide was used as a plasticiser and as a stabiliser. Molten acetamide was frequently used as a solvent in chemical synthesis. It also acts as a solubiliser; its mere addition renders many sparingly soluble compounds more soluble in water.
Internet Links for Acetamide
mindat.org URL:
https://www.mindat.org/min-13.html
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Please feel free to link to this page.
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References for Acetamide
Localities for Acetamide
Showing 4 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Poland | |
| Kruszewski (2012) +1 other reference |
Ukraine (TL) | |
| [ZVMO 104 (1975) +3 other references |
USA | |
| - (2005) |
| Mineralogical Society of America - ... |
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Burnside, Northumberland County, Pennsylvania, USA