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 Mindat
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom 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

Congolite

This page is currently not sponsored. Click here to sponsor this page.
Flag of the Republic of the Congo
Formula:
(Fe2+,Mg)3(B7O13)Cl
Colour:
Pale red, pink
Hardness:
6½ - 7½
Crystal System:
Trigonal
Member of:
Name:
Named by E. Wendling, R.V. Hodenberg, and R. Kühn in 1972 after the country where the mineral was first discovered, the Republic of Congo (Brazzaville).
Dimorph of:
Boracite Group. The Fe2+ analogue of Trembathite. The trigonal dimorph of Ericaite.


Hide all sections | Show all sections

Classification of CongoliteHide

Approved
First Published:
1972
6.GA.10

6 : BORATES
G : Heptaborates and other megaborates
A : Tekto-heptaborates
25.6.2.1

25 : ANHYDROUS BORATES CONTAINING HYDROXYL OR HALOGEN
6 : Hexaborates
10.1.19

10 : Borates with other anions
1 : Borates with halide

Physical Properties of CongoliteHide

Transparency:
Transparent
Colour:
Pale red, pink
Hardness:
6½ - 7½ on Mohs scale

Optical Data of CongoliteHide

Type:
Uniaxial (-)
RI values:
nω = 1.755 nε = 1.731
Max Birefringence:
δ = 0.024
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
High

Chemical Properties of CongoliteHide

Formula:
(Fe2+,Mg)3(B7O13)Cl
IMA Formula:
Fe2+3B7O13Cl

Crystallography of CongoliteHide

Crystal System:
Trigonal
Class (H-M):
3m - Ditrigonal Pyramidal
Space Group:
R3c
Cell Parameters:
a = 8.62 Å, c = 21.05 Å
Ratio:
a:c = 1 : 2.442
Unit Cell V:
1,354.56 ų (Calculated from Unit Cell)

Type Occurrence of CongoliteHide

General Appearance of Type Material:
grains from drill core

Synonyms of CongoliteHide

Other Language Names for CongoliteHide

German:Congolit
Spanish:Congolita

Relationship of Congolite to other SpeciesHide

Member of:
Other Members of this group:
BoraciteMg3(B7O13)ClOrth. mm2 : Pca21
ChambersiteMn2+3(B7O13)ClOrth. mm2 : Pca21
EricaiteFe2+3(B7O13)ClOrth.
Trembathite(Mg,Fe)3(B7O13)ClTrig.

Common AssociatesHide

Associated Minerals Based on Photo Data:
Sylvite2 photos of Congolite associated with Sylvite on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

6.GA.05BoraciteMg3(B7O13)ClOrth. mm2 : Pca21
6.GA.05ChambersiteMn2+3(B7O13)ClOrth. mm2 : Pca21
6.GA.05EricaiteFe2+3(B7O13)ClOrth.
6.GA.10Trembathite(Mg,Fe)3(B7O13)ClTrig.
6.GA.30KorzhinskiteCa(B2O4) · H2O

Related Minerals - Dana Grouping (8th Ed.)Hide

25.6.2.2Trembathite(Mg,Fe)3(B7O13)ClTrig.

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

10.1.1TeepleiteNa2[B(OH)4]ClTet. 4/mmm (4/m 2/m 2/m) : P4/nmm
10.1.2BandyliteCu[B(OH)4]ClTet. 4/mmm (4/m 2/m 2/m) : P4/nmm
10.1.3BerboriteBe2(BO3)(OH,F) · H2OTrig.
10.1.4FluoboriteMg3(BO3)(F,OH)3Hex.
10.1.5BoraciteMg3(B7O13)ClOrth. mm2 : Pca21
10.1.6KarliteMg7(BO3)3(OH,Cl)5Orth.
10.1.7ShabyniteMg5(BO3)(OH)5(Cl,OH)2 · 4H2OMon.
10.1.8/9/10HilgarditeCa2B5O9Cl · H2OTric. 1 : P1
10.1.11SolongoiteCa2(H3B3O7)(OH)ClMon.
10.1.12HydrochlorboriteCa4B8O15Cl2 · 21H2OMon.
10.1.13EkateriniteCa2(B4O7)(Cl,OH)2 · 2H2OHex.
10.1.14VolkovskiteKCa4[B5O8OH]4[B(OH)3]2Cl · 4H2OTric. 1 : P1
10.1.15ChelkariteCaMgB2O4(Cl,OH)2 · 5H2O Or near, with Cl:OH = 3:1Orth.
10.1.16JohachidoliteCaAlB3O7Orth. mmm (2/m 2/m 2/m) : Cmma
10.1.17SatimoliteKNa2Al4[Cl|B2O5]3 · 13H2OOrth.
10.1.18ChambersiteMn2+3(B7O13)ClOrth. mm2 : Pca21
10.1.20EricaiteFe2+3(B7O13)ClOrth.

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 CongoliteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Wendling, E., Hodenberg, R.V., Kühn, R. (1972) Congolit, der trigonale eisenboracit. Kali und Steinsalz: 6: 1-3.
Fleischer, M. (1972) New mineral names. American Mineralogist: 57: 1311-1317.
Dowty, E., Clark, J.R. (1973) Crystal-structure refinements for orthorhombic boracite, Mg3B7O13Cl, and a trigonal, iron-rich analogue. Zeitschrift für Kristallographie: 138: 64-99.
Nelmes, R.J. (1974) Structural studies of boracites. A review of the properties of boracites. Journal of Physics C: Solid State Physics: 7: 3841-3855.
Mendoza-Alvarez, M.E., Yvon, K., Depmeier, W., Schmid, H. (1985) Structure refinement of trigonal iron-chlorine boracite. Acta Crystallographica: C41: 1551-1552.
Burns, P.C. (1995) X-ray powder diffraction data for the identification of boracite-group minerals. Powder Diffraction: 10: 250-260.
Burns, P.C., Carpenter, M.A. (1996) Phase transitions in the series boracite-trembathite-congolite: phase relations. Canadian Mineralogist: 34: 881-892.
Grew, E.S., Anovitz, L.M. (1996) BORON: Mineralogy, Petrology and Geochemistry, second edition, as revised (2002).
Burns, P.C., Carpenter, M.A. (1997) Phase transitions in the series boracite – trembathite – congolite: an infrared spectroscopic study. The Canadian Mineralogist: 35: 189-202.
Grice, J.D., Gault, R.A., Van Velthuizen, J. (2005) Borate minerals of the Penobsquis and Millstream deposits, southern New Brunswick, Canada. The Canadian Mineralogist: 43: 1469-1487.
Wachowiak, J., Pieczka, A., (2012) Congolite and trembathite from the Kłodawa Salt Mine, Central Poland: records of the thermal history of the parental salt dome. The Canadian Mineralogist: 50: 1387-1399.

Internet Links for CongoliteHide

Localities for CongoliteHide

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.
Canada
 
  • New Brunswick
    • Kings Co.
      • Cardwell Parish
CM 43, 1469-1487
Grice, J. L. (2002): Borate Minerals from the Penobsquis and Millstream Deposits of Southern New Brunswick, Canada. Bergverksmuseets Skrift 20, 27-33
      • Studholm Parish
Grice, J.D., Gault, R.A., Van Velthuizen, J. (2005) Borate minerals of the Penobsquis and Millstream deposits, southern New Brunswick, Canada. The Canadian Mineralogist: 43: 1469-1487.
Germany
 
  • Thuringia
    • Bleicherode
Fleischer M (1972) New mineral names. American Mineralogist 57, 1311-1317
Poland
 
  • Wielkopolskie
PIECZKA, A. & WACHOWIAK, J. (2012) CONGOLITE FROM THE KŁODAWA SALT MINE (CENTRAL POLAND) AND ITS IMPORTANCE AT EVALUATION OF METAMORPHIC CONDITIONS IN THE SALT DOME. Acta Mineralogica-Petrographica, Abstract Series, Szeged, Vol. 7, 2012 , 107. [http://www.mineral.hermuz.hu/acta_07/pdf/107-Pieczka.pdf]; Wachowiak, J., Pieczka, A. (2016): Motukoreaite from the Kłodawa Salt Dome, Central Poland. Mineralogical Magazine, 80, 277-289
Republic of Congo (Brazzaville)
 
  • Brazzaville Department
American Mineralogist (1972): 57: 1315.
American Mineralogist (1972): 57: 1315.
UK
 
  • England
    • North Yorkshire
      • Loftus
Bart Cannon analyses
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: October 22, 2017 10:53:03 Page generated: October 11, 2017 03:59:24
Go to top of page