Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat Articles
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsThe ElementsUsersBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery


This page is currently not sponsored. Click here to sponsor this page.
Colourless; colourless in transmitted light
Crystal System:
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.

Hide all sections | Show all sections

Physical Properties of Hilgardite-3TcHide

Colourless; colourless in transmitted light
On {010} and {100}.

Optical Data of Hilgardite-3TcHide

Biaxial (+)
r > v

Crystallography of Hilgardite-3TcHide

Crystal System:
Class (H-M):
1 - Pedial
Space Group:
Cell Parameters:
a = 11.24 Å, b = 22.28 Å, c = 6.2 Å
α = 90°, β = 90°, γ = 91.2°
a:b:c = 0.504 : 1 : 0.278
Unit Cell V:
1,552.31 ų (Calculated from Unit Cell)
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-3TcHide

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

Synonyms of Hilgardite-3TcHide

Other Language Names for Hilgardite-3TcHide

Common AssociatesHide

Associated Minerals Based on Photo Data:
Hilgardite4 photos of Hilgardite-3Tc associated with Hilgardite on mindat.org.
Boracite4 photos of Hilgardite-3Tc associated with Boracite on mindat.org.

Other InformationHide

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-3TcHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
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-3TcHide

Localities for Hilgardite-3TcHide

This 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.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
  • Yunnan
    • Pu'er
      • Jiangcheng Co.
Li, M., Yan, M., Wang, Z., Liu, X., Fang, X., & Li, J. (2015). The origins of the Mengye potash deposit in the Lanping–Simao Basin, Yunnan Province, Western China. Ore Geology Reviews, 69, 174-186.
  • England
    • North Yorkshire
      • Redcar and Cleveland
        • Loftus
Milne, J. K. (1978). The potash deposits and their associates in the area of the Boulby mine, Cleveland. PhD thesis University of Edinburgh
      • Scarborough
Smith, F.W., Dearlove, J.P.L., Kemp, S.J., Bell, C.P., Milne, C.J. and Pottas, T.L. (2014) Potash – Recent exploration developments in North Yorkshire. Pp. 45-50 in Hunger, E., Brown, T. J. and Lucas, G. (Eds.) Proceedings of the 17th Extractive Industry Geology Conference, EIG Conferences Ltd. 202pp
  • 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  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2019, 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 26, 2019 18:22:32 Page generated: March 24, 2019 16:02:22
Go to top of page