Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Urea

This page is currently not sponsored. Click here to sponsor this page.
Formula:
CO(NH2)2
System:
Tetragonal
Colour:
Colourless, pale yellow, ...
Name:
The name is the common trivial name of this compound (derived from Greek "oura", urine). The systematic name is carbonic acid diamide.
Derived from bat guano and urine, stable only under very arid conditions.


Classification of Urea

Approved, 'Grandfathered' (first described prior to 1959)
Approval Year:
1972
First Published:
1973
10.CA.35

10 : ORGANIC COMPOUNDS
C : Miscellaneous Organic Minerals
A : Miscellaneous Organic Minerals
50.4.6.1

50 : ORGANIC COMPOUNDS
4 : Miscellaneous
32.13

32 :

Physical Properties of Urea

Diaphaneity (Transparency):
Translucent
Colour:
Colourless, pale yellow, pale brown
Streak:
yellowish white
Density:
1.33 g/cm3 (Measured)    
Comment:
Sink- float method in Nujol and α-bromonaphthalene.

Optical Data of Urea

Type:
Uniaxial (+)
RI values:
nω = 1.484 nε = 1.603
Max Birefringence:
δ = 0.119
Image shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:
Low

Chemical Properties of Urea

Formula:
CO(NH2)2
Elements listed in formula:

Crystallography of Urea

Crystal System:
Tetragonal
Class (H-M):
4 2m - Scalenohedral
Space Group:
P4 21m
Cell Parameters:
a = 5.646(1) Å, c = 4.701(1) Å
Ratio:
a:c = 1 : 0.833
Unit Cell Volume:
V 149.86 ų (Calculated from Unit Cell)
Z:
2

Type Occurrence of Urea

General Appearance of Type Material:
Damp incoherent mass of crystals.
Place of Conservation of Type Material:
Western Australia Museum, Perth, Australia, S4688.
Geological Setting of Type Material:
Cave guano from warm arid environment.
Associated Minerals at Type Locality:

Relationship of Urea to other Species

10.CA.Tholins(C,H,N)
10.CA.05RefikiteC20H32O2
10.CA.10FlagstaffiteC10H22O3
10.CA.15HoeliteC14H8O2
10.CA.20AbelsoniteNiC31H32N4
10.CA.25KladnoiteC6H4(CO)2NH
10.CA.30GuanineC5H3(NH2)N4O
10.CA.30Tinnunculite (of Chesnokov & Shcherbakova)C10H12N8O8
10.CA.40UriciteC5H4N4O3
32.1EvenkiteC23H48
32.2FichteliteC19H34
32.3SimonelliteC19H24
32.4KratochvíliteC13H10
32.5IdrialiteC22H14
32.6CarpathiteC24H12
32.7RefikiteC20H32O2
32.8FlagstaffiteC10H22O3
32.9HoeliteC14H8O2
32.10KladnoiteC6H4(CO)2NH
32.11AcetamideCH3CONH2
32.12GuanineC5H3(NH2)N4O
32.14UriciteC5H4N4O3
32.15AbelsoniteNiC31H32N4

Other Names for Urea

Name in Other Languages:
German:Harnstoff

Other Information

Special Storage/
Display Requirements:
Stable only under very arid conditions.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Urea

Reference List:
Wohler, M.F. (1828) Artificial formation of urea. The Philosophical Magazine: 4: 309-310.

Worsham, J., Levy, H., Peterson, S. (1957) The positions of hydrogen atoms in urea by neutron diffraction. Acta Crystallographica: 10: 319-323.

Bridge, P.J. (1973) Urea, a new mineral, and neotype phosphammite from Western Australia. Mineralogical Magazine: 39: 346–348.

Fleischer, M. (1974) New mineral names. American Mineralogist: 59: 873-875.

Pryor, A.W., Sanger, P.L. (1970) Collection and interpretation of neutron diffraction measurements on urea. Acta Crystallographica: A26: 543-558.

Mullen, H.E (1978) A simple refinement of density distributions of bonding electrons. V. Bond electron density distribution in Urea, CO(NH2)2, at 123 K. Acta Crystallographica: B34: 1624-1627.

Swaminathan, S., Craven, B.M. (1984) The crystal structure and molecular thermal motion of urea at 12, 60 and 123 K from neutron diffraction. Acta Crystallographica: B40: 300-306.

Acta Crystallographica (1999).

Internet Links for Urea

mindat.org URL:
https://www.mindat.org/min-4117.html
Please feel free to link to this page.

Localities for Urea

map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
(TL) indicates type locality for a valid mineral species. (FRL) indicates first recorded locality for everything else. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
Australia (TL)
 
  • Western Australia
    • Laverton Shire
      • Lake Rason
Mineralogical Magazine (1973): 39: 346-348.
Saudi Arabia
 
  • Mintaqah Makkah
Saudi Geological Survey Open-File Report SGS-OF-2004-12, 68 p.
USA
 
  • Arizona
    • La Paz Co.
      • Buckskin Mts
        • Santa Maria District (Planet District; Swansea District; Bill Williams District)
          • Planet
A.R. Kampf
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2017, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: April 26, 2017 20:37:32 Page generated: March 21, 2017 02:17:46
Go to top of page