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 GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportAdd Glossary Item
StatisticsMember 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

Hilgardite-3Tc

This page is currently not sponsored. Click here to sponsor this page.
System:
Triclinic
Colour:
Colourless; colourless ...
Hardness:
5
Name:
Named for Eugene Woldemar Hilgard (1833-1916), German-American geologist, one of the first to describe the Loiuisiana salt dome deposits.
A polytype of Hilgardite

Originally described from Choctaw Salt Dome, Iberville Parish, Louisiana, USA.

Classification of Hilgardite-3Tc

mindat.org URL:
http://www.mindat.org/min-9762.html
Please feel free to link to this page.

Physical Properties of Hilgardite-3Tc

Vitreous
Diaphaneity (Transparency):
Transparent
Colour:
Colourless; colourless in transmitted light
Hardness (Mohs):
5
Cleavage:
Perfect
On {010} and {100}.

Crystallography of Hilgardite-3Tc

Crystal System:
Triclinic
Class (H-M):
1 - Pedial
Space Group:
P1
Cell Parameters:
a = 11.24Å, b = 22.28Å, c = 6.2Å
α = 90°, β = 90°, γ = 91.2°
Ratio:
a:b:c = 0.504 : 1 : 0.278
Z:
2
Morphology:
Only occurs as oriented intergrowths with hilgardite. The intergrowths are comprised of two partly merged individual crystals of Hilgardite-3Tc, one right-handed and one left-handed, in apparent twin position. These are attached by the positive end of [100] to (100) of a single Hilgardite crystal. Common forms include b, p, t.

Epitaxial Relationships of Hilgardite-3Tc

Epitaxial Minerals:
HilgarditeCa2B5O9Cl · H2O
Epitaxi Comments:
Parahilgardite {100} [001] parallel with Hilgardite {100} [001], with the {010} cleavages of the two minerals inclined at 1°12'.

Optical Data of Hilgardite-3Tc

Type:
Biaxial (+)
Dispersion:
r > v

Other Names for Hilgardite-3Tc

Name in Other Languages:

Other Information

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 Hilgardite-3Tc

Reference List:
Hurlbut (1938) American Mineralogist: 23: 765 (as Parahilgardite).

Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged: 383 (as Parahilgardite).

American Mineralogist (1985): 70: 636-637.

Internet Links for Hilgardite-3Tc

Localities for Hilgardite-3Tc

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.
USA
 
  • Louisiana
    • Iberville Parish
      • Plaquemine
Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 383, 384; Rocks & Minerals: 69(3): 156-162.; American Mineralogist 23:898
Mineral and/or Locality  
Copyright © mindat.org 1993-2015, 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: March 1, 2015 16:44:54 Page generated: February 9, 2015 18:43:21