Mindat Logo

Robertsite

Formula:
Ca
 
3
Mn
3+
4
[(OH)
 
3
|(PO
 
4
)
 
2
]
 
2
· 3H
 
2
O
System:MonoclinicColour:Red, red-brown, deep ...
Hardness:
Name:Named after Willard Lincoln Roberts, professor of mineralogist.
This page provides mineralogical data about Robertsite.

Classification of Robertsite

IMA status:Approved 1973
Strunz 8th edition ID:7/D.30-50
Nickel-Strunz 10th (pending) edition ID:8.DH.30

8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
H : With large and medium-sized cations, (OH, etc.):RO4 < 1:1
Dana 8th edition ID:42.8.4.2

42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
8 : (AB)5(XO4)3Zq·xH2O
Hey's CIM Ref.:19.12.6

19 : Phosphates
12 : Phosphates of Mn
mindat.org URL:http://www.mindat.org/min-3431.html
Please feel free to link to this page.

Type Occurrence of Robertsite

Type Locality:Tip Top Mine, Fourmile, Custer District, Custer Co., South Dakota, USA
Year of Discovery:1974

Physical Properties of Robertsite

Lustre:Resinous, Silky
Diaphaneity (Transparency):Translucent, Translucent on thin edges
Colour:Red, red-brown, deep red, bronzy, black
Streak:Chocolate-brown
Hardness (Mohs):

Crystallography of Robertsite

Crystal System:Monoclinic

Optical Data of Robertsite

Type:Biaxial (-)
RI values: nα = 1.775 nβ = 1.820 nγ = 1.820
2V:Measured: 8°
Maximum Birefringence:δ = 0.045

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Very High
Dispersion:relatively weak

Chemical Properties of Robertsite

Formula:
Ca
 
3
Mn
3+
4
[(OH)
 
3
|(PO
 
4
)
 
2
]
 
2
· 3H
 
2
O
Essential elements:Ca, H, Mn, O, P
All elements listed in formula:Ca, H, Mn, O, P

Relationship of Robertsite to other Species

Series:Forms a series with Arseniosiderite (see here)
Related Minerals - Nickel-Strunz Grouping):
8.DH.05Minyulite
KAl
 
2
[(OH,F)|(PO
 
4
)
 
2
] · 4H
 
2
O
8.DH.10Leucophosphite
KFe
3+
2
[OH|(PO
 
4
)
 
2
] · 2H
 
2
O
8.DH.10Spheniscidite
(NH
 
4
,K)(Fe
3+
 
,Al)
 
2
[OH|(PO
 
4
)
 
2
] · 2H
 
2
O
8.DH.10Tinsleyite
KAl
 
2
[OH|(PO
 
4
)
 
2
] · 2H
 
2
O
8.DH.15Jahnsite-(CaMnFe)
CaMn
2+
 
Fe
2+
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Jahnsite-(CaMnMg)
CaMn
2+
 
(Mg,Fe
2+
 
)
 
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Jahnsite-(CaMnMn)
CaMn
2+
 
Mn
2+
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Keckite
(Ca,Mg)(Mn
2+
 
,Zn)
 
2
Fe
3+
3
(PO
 
4
)
 
4
(OH)
 
3
· 2H
 
2
O
8.DH.15Rittmannite
(Mn
2+
 
,Ca)Mn
2+
 
(Fe
2+
 
,Mn
2+
 
,Mg)
 
2
(Al,Fe
3+
 
)
 
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Whiteite-(CaFeMg)
Ca(Fe
2+
 
,Mn
2+
 
)Mg
 
2
Al
 
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Whiteite-(CaMnMg)
CaMn
2+
 
Mg
 
2
Al
 
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Whiteite-(MnFeMg)
(Mn
2+
 
,Ca)(Fe
2+
 
,Mn
2+
 
)Mg
 
2
Al
 
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Jahnsite-(MnMnMn)
Mn
2+
 
Mn
2+
 
Mn
2+
2
Fe
3+
2
(PO
 
4
)
 
4
](OH)
 
2
· 8H
 
2
O
8.DH.15Kaluginite
(Mn
2+
 
,Ca)MgFe
3+
 
[OH|(PO
 
4
)
 
2
] · 4H
 
2
O
8.DH.15Jahnsite-(CaFeFe)
CaFeFe
 
2
Fe
 
2
(PO
 
4
)
 
4
(OH)
 
2
·8H
 
2
O
8.DH.15Jahnsite-(NaFeMg)
NaFe
3+
 
Mg
 
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Jahnsite-(NaMnMg)
NaMnMg
 
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.15Jahnsite-(CaMgMg)
CaMgMg
 
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.20Manganosegelerite
(Mn
2+
 
,Ca)(Mn
2+
 
,Fe
2+
 
,Mg)Fe
3+
 
(PO
 
4
)
 
2
(OH)
 
2
· 4H
 
2
O
8.DH.20Overite
CaMgAl[OH|(PO
 
4
)
 
2
] · 4H
 
2
O
8.DH.20Segelerite
Ca
 
2
Mg
 
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
8.DH.20Wilhelmvierlingite
CaMnFe
3+
 
[OH|(PO
 
4
)
 
2
] · 2H
 
2
O
8.DH.20Juonniite
CaMgSc(PO
 
4
)
 
2
(OH)·4H
 
2
O
8.DH.25Calcioferrite
Ca
 
2
Fe
3+
2
[OH|(PO
 
4
)
 
3
] · 7H
 
2
O
8.DH.25Kingsmountite
Ca
 
4
(Fe
2+
 
,Mn
2+
 
)Al
 
4
[(OH)
 
2
|(PO
 
4
)
 
3
]
 
2
· 12H
 
2
O
8.DH.25Montgomeryite
Ca
 
4
MgAl
 
4
[(OH)
 
2
|(PO
 
4
)
 
3
]
 
2
· 12H
 
2
O
8.DH.25Zodacite
Ca
 
4
Mn
2+
 
Fe
3+
4
[(OH)
 
2
|(PO
 
4
)
 
3
]
 
2
· 12H
 
2
O
8.DH.30Arseniosiderite
Ca
 
2
Fe
3+
3
[O
 
2
|(AsO
 
4
)
 
3
] · 3H
 
2
O
8.DH.30Kolfanite
Ca
 
2
Fe
3+
2
[O
 
2
|(AsO
 
4
)
 
3
] · 2H
 
2
O
8.DH.30Mitridatite
Ca
 
2
Fe
3+
3
[O
 
2
|(PO
 
4
)
 
3
] · 3H
 
2
O
8.DH.30Pararobertsite
Ca
 
2
Mn
3+
3
[O
 
2
|(PO
 
4
)
 
3
] · 3H
 
2
O
8.DH.30Sailaufite
Ca
 
2
Mn
3+
3
[O|CO
 
3
|(AsO
 
4
)
 
2
] · 3H
 
2
O
8.DH.35Mantienneite
KMg
 
2
Al
 
2
Ti[(OH)
 
3
|(PO
 
4
)
 
4
] · 15H
 
2
O
8.DH.35Paulkerrite
K(Mg,Mn
2+
 
)
 
2
(Fe
3+
 
,Al,Ti,Mg)
 
2
Ti(PO
 
4
)
 
4
(OH)
 
3
· 15H
 
2
O
8.DH.35Benyacarite
(H
 
2
O,K)
 
2
(Mn
2+
 
,Fe
2+
 
)
 
2
(Fe
3+
 
,Ti)
 
2
Ti[(O,F)
 
2
|(PO
 
4
)
 
4
] · 14H
 
2
O
8.DH.40Xanthoxenite
Ca
 
4
Fe
3+
2
[OH|(PO
 
4
)
 
2
]
 
2
· 3H
 
2
O
8.DH.45Mahnertite
NaCu
 
3
(AsO
 
4
)
 
2
Cl · 5H
 
2
O
8.DH.50Andyrobertsite
KCdCu
 
5
[H
 
2
AsO4|(AsO
 
4
)
 
4
] · 2H
 
2
O
8.DH.50Calcioandyrobertsite
KCaCu
 
5
[H
 
2
AsO
 
4
|(AsO
 
4
)
 
4
] · 2H
 
2
O
8.DH.55Englishite
K
 
3
Na
 
2
Ca
 
10
Al
 
15
[OH|(PO
 
4
)
 
3
]
 
7
· 26H
 
2
O
8.DH.60Bouazzerite
Bi
 
6
(Mg,Co)
 
11
Fe
3+
14
(AsO
 
4
)
 
18
O
 
12
(OH)
 
4
(H
 
2
O)
 
86
Related Minerals - Hey's Index Grouping:
19.12.1Metaswitzerite
Mn
 
3
(PO
 
4
)
 
2
·4H
 
2
O
19.12.2Bermanite
Mn
2+
 
Mn
3+
2
[OH|PO
 
4
]
 
2
· 4H
 
2
O
19.12.3Natrophilite
NaMn
2+
 
[PO
 
4
]
19.12.4Sidorenkite
Na
 
3
Mn
2+
 
[PO
 
4
|CO
 
3
]
19.12.5Niahite
(NH
 
4
)(Mn
2+
 
,Mg)[PO
 
4
] · H
 
2
O
19.12.7Pararobertsite
Ca
 
2
Mn
3+
3
[O
 
2
|(PO
 
4
)
 
3
] · 3H
 
2
O
19.12.8Sinkankasite
H
 
2
Mn
2+
 
Al[OH|(PO
 
4
)
 
2
] · 6H
 
2
O
19.12.9Mangangordonite
Mn
2+
 
Al
 
2
[OH|PO
 
4
]
 
2
· 8H
 
2
O
19.12.10Heterosite
(Fe
3+
 
,Mn
3+
 
)[PO
 
4
]
19.12.11Purpurite
(Mn
3+
 
,Fe
3+
 
)[PO
 
4
]
19.12.12Wolfeite
(Fe
2+
 
,Mn
2+
 
)
 
2
[OH|PO
 
4
]
19.12.13Triploidite
(Mn
2+
 
,Fe
2+
 
)
 
2
[OH|PO
 
4
]
19.12.14Lipscombite
(Fe
2+
 
,Mn
2+
 
)Fe
3+
2
[OH|PO
 
4
]
 
2
19.12.15Frondelite
Mn
2+
 
Fe
3+
4
[(OH)
 
5
|(PO
 
4
)
 
3
]
19.12.16Rockbridgeite
Fe
2+
 
Fe
3+
4
[(OH)
 
5
|(PO
 
4
)
 
3
]
19.12.17Kryzhanovskite
MnFe
 
2
(PO
 
4
)
 
2
(OH)
 
2
·H
 
2
O
19.12.18Landesite
Mn
2+
3-x
Fe
3+
x
[(OH)
 
x
|(PO
 
4
)
 
2
] · (3-x)H
 
2
O
19.12.19Phosphoferrite
(Fe,Mn)
 
3
(PO
 
4
)
 
2
·3H
 
2
O
19.12.20Reddingite
(Mn,Fe)
 
3
(PO
 
4
)
 
2
·3H
 
2
O
19.12.21Earlshannonite
Mn
2+
 
Fe
3+
2
(PO
 
4
)
 
2
(OH)
 
2
·4H
 
2
O
19.12.22Hureaulite
(Mn,Fe)
 
5
H
 
2
(PO
 
4
)
 
4
·4H
 
2
O
19.12.23Switzerite
(Mn,Fe)
 
3
(PO
 
4
)
 
2
·7H
 
2
O
19.12.24Laueite
Mn
2+
 
Fe
3+
2
[OH|PO
 
4
]
 
2
· 8H
 
2
O
19.12.25Pseudolaueite
Mn
2+
 
Fe
3+
2
[OH|PO
 
4
]
 
2
· 8H
 
2
O
19.12.26Strunzite
Mn
2+
 
Fe
3+
2
[OH|PO
 
4
]
 
2
· 6H
 
2
O
19.12.27Stewartite
Mn
2+
 
Fe
3+
2
[OH|PO
 
4
]
 
2
· 8H
 
2
O
19.12.28Alluaudite
(Na,Ca)Mn
2+
 
(Fe
3+
 
,Mn
2+
 
,Fe
2+
 
,Mg)
 
2
(PO
 
4
)
 
3
19.12.29Ferroalluaudite
(Na,Ca)Fe
2+
 
(Fe
3+
 
,Mn
2+
 
,Fe
2+
 
)
 
2
(PO
 
4
)
 
3
19.12.30Fillowite
{Mn
2+
 
}{Na
 
8
}{Ca
 
4
Na
 
4
}{(Mn
2+
 
,Fe
2+
 
)
 
43
}[PO
 
4
]
 
36
19.12.31Johnsomervilleite
{Ca}{Na
 
6
[ ]
 
2
}{Ca
 
6
Na
 
2
}{(Fe
2+
 
,Mg,Mn
2+
 
)
 
43
}[PO
 
4
]
 
36
19.12.32Wicksite
NaCa
 
2
(Fe
2+
 
,Mn
2+
 
)
 
4
MgFe
3+
 
[PO
 
4
]
 
6
· 2H
 
2
O
19.12.33Dickinsonite-(KMnNa)
{KNa}{Mn
2+
 
[ ]}{Ca}{Na
 
3
}{Mn
2+
13
}{Al}[(OH)
 
2
|(PO
 
4
)
 
12
]
19.12.34Sarcopside
(Fe
2+
 
,Mn
2+
 
,Mg)
 
3
[PO
 
4
]
 
2
19.12.35Ludlamite
(Fe,Mn,Mg)
 
3
(PO
 
4
)
 
2
·4H
 
2
O
19.12.36Graftonite
(Fe
2+
 
,Mn
2+
 
,Ca)
 
3
[PO
 
4
]
 
2
19.12.37Wilhelmvierlingite
CaMnFe
3+
 
[OH|(PO
 
4
)
 
2
] · 2H
 
2
O
19.12.38Fairfieldite
Ca
 
2
(Mn
2+
 
,Fe
2+
 
)[PO
 
4
]
 
2
· 2H
 
2
O
19.12.39Beusite
(Mn
2+
 
,Fe
2+
 
,Ca,Mg)
 
3
[PO
 
4
]
 
2
19.12.40Messelite
Ca
 
2
(Fe
2+
 
,Mn
2+
 
)[PO
 
4
]
 
2
· 2H
 
2
O
19.12.41Jahnsite-(CaMnFe)
CaMn
2+
 
Fe
2+
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
19.12.42Jahnsite-(CaMnMn)
CaMn
2+
 
Mn
2+
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
19.12.43Jahnsite-(CaMnMg)
CaMn
2+
 
(Mg,Fe
2+
 
)
 
2
Fe
3+
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
19.12.44Keckite
(Ca,Mg)(Mn
2+
 
,Zn)
 
2
Fe
3+
3
(PO
 
4
)
 
4
(OH)
 
3
· 2H
 
2
O
19.12.45Stanfieldite
Ca
 
7
Ca
 
2
Mg
 
9
[PO
 
4
]
 
12
19.12.46Laubmannite
(Fe
2+
 
,Mn
2+
 
,Ca)
 
3
Fe
3+
6
[(OH)
 
3
|PO
 
4
]
 
4
19.12.47Zodacite
Ca
 
4
Mn
2+
 
Fe
3+
4
[(OH)
 
2
|(PO
 
4
)
 
3
]
 
2
· 12H
 
2
O
19.12.48Hagendorfite
NaCaMn
2+
 
Fe
2+
2
(PO
 
4
)
 
3
19.12.49Maghagendorfite
NaMn(Mg,Fe,Fe)
 
3
(PO
 
4
)
 
3
19.12.50Varulite
NaCaMn
2+
 
Mn
2+
2
(PO
 
4
)
 
3
19.12.51Griphite
Na
 
4
Li
 
2
Ca
 
6
(Mn
2+
 
,Fe
2+
 
,Mg)
 
19
Al
 
8
[(F,OH)|(PO
 
4
)
 
3
]
 
8
19.12.52Attakolite
(Ca,Sr)Mn(Al,Fe)
 
4
[(OH)
 
4
|(SiO
 
4
,PO
 
4
)|(HPO
 
4
,PO
 
4
)
 
3
]
19.12.53Arrojadite-(KFe)
{KNa}{Fe
2+
 
[ ]}{Ca}{Na
 
2
[ ]}{Fe
2+
13
}{Al}[(OH)
 
2
|HPO
 
4
|(PO
 
4
)
 
11
]
19.12.54Lun'okite
(Mn,Ca)(Mg,Fe,Mn)Al(PO
 
4
)
 
2
OH·4H
 
2
O
19.12.55Eosphorite
(Mn
2+
 
,Fe
2+
 
)Al[(OH)
 
2
|PO
 
4
] · H
 
2
O
19.12.56Ernstite
(Mn
2+
 
,Fe
3+
 
)Al[(OH,O)
 
2
|PO
 
4
] · H
 
2
O
19.12.57Childrenite
(Fe
2+
 
,Mn
2+
 
)Al[(OH)
 
2
|PO
 
4
] · H
 
2
O
19.12.58Bobfergusonite
Na
 
2
Mn
 
5
FeAl(PO
 
4
)
 
6
19.12.59Qingheiite
NaMn
3+
 
Mg(Al,Fe
3+
 
)[PO
 
4
]
 
3
19.12.60Whiteite-(CaFeMg)
Ca(Fe
2+
 
,Mn
2+
 
)Mg
 
2
Al
 
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
19.12.61Whiteite-(CaMnMg)
CaMn
2+
 
Mg
 
2
Al
 
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
19.12.62Whiteite-(MnFeMg)
(Mn
2+
 
,Ca)(Fe
2+
 
,Mn
2+
 
)Mg
 
2
Al
 
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
19.12.63Rittmannite
(Mn
2+
 
,Ca)Mn
2+
 
(Fe
2+
 
,Mn
2+
 
,Mg)
 
2
(Al,Fe
3+
 
)
 
2
(PO
 
4
)
 
4
(OH)
 
2
· 8H
 
2
O
19.12.64Zanazziite
Ca
 
2
(Mg,Fe)(Mg,Fe,Al)
 
4
Be
 
4
[(OH)
 
4
|(PO
 
4
)
 
6
] · 6H
 
2
O
19.12.65Samuelsonite
(Ca,Ba)Ca
 
8
Fe
2+
2
Mn
2+
2
Al
 
2
[(OH)
 
2
|(PO
 
4
)
 
10
]

Other Names for Robertsite

Synonyms:
IMA1973-024
German names:
Robertsit
Spanish names:
Robertsita

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Robertsite

Reference List:Moore, Paulus B. (1974), Jahnsite, segelerite, robertsite, three new transition metal phosphates species: American Mineralogist: 59: 48-60.

Mineralogical Magazine: 52: 505-508.

Internet Links for Robertsite

Search Engines:
  • Look for Robertsite on Google
  • Look for Robertsite images on Google
  • External Links:
  • Look for Robertsite on Webmineral
  • Look for Robertsite on Athena Mineralogy
  • Look for Robertsite on Wikipedia
  • Look for Robertsite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Search for Robertsite in the Natural History Museum (London) online catalogue
  • Robertsite details from Handbook of Mineralogy (PDF)
  • Mineral Dealers:
  • rare and unusual minerals mainly crystallized
  • Fine Minerals from Dan Weinrich Minerals
  • Wendel Minerals - Auktion & Shop
  • Find Robertsite on www.crystalclassics.co.uk
  • Buy fine minerals and gemstones from Pala International
  • Buy from David K Joyce minerals
  • Fabre Minerals - search for Robertsite specimens
  • Wright's Rock Shop - excellent mineral specimens since 1970
  • Buy Fine Minerals from mineralsweb.com
  • The Arkenstone - Fine Minerals
  • Search for Robertsite on minvision.com
  • Lapis Mineral Magazin
  • Jobs:
  • Mining & Geology Jobs
  • Page Sponsor

    Sponsorship:This page is currently not sponsored. Click here to find out how you can sponsor this page.

    Localities for Robertsite

    The 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.
    These maps work faster with Firefox!
    (TL) indicates type locality. ? 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.
    Ethiopia
     
    • Sidamo Province
      • Lake Rudolf (Lake Turkana)
        • Lower Omo Valley
    American Mineralogist, Vol. 64, 1979, pp. 169-171.
    France
     
    • Auvergne
      • Allier
        • Ebreuil
          • Echassières
    J.M. Boisson et al. : "Filon Sainte Barbe, Commune d'Echassières, Allier, France", Le Cahier des Micromonteurs, 2000, 4, 3-46
    Germany
     
    • Bavaria
      • Lower Bavaria
        • Bavarian Forest
          • Zwiesel
            • Rabenstein
    Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
      • Upper Palatinate
        • Oberpfälzer Wald
          • Vohenstrauß
            • Waidhaus
              • Hagendorf
    http://www.berthold-weber.de/h_miner.htm
    Namibia
     
    • Erongo Region
      • Karibib District
        • Usakos
    Keller, P. (1974): Phosphatmineralien aus Pegmatiten Sudwestafrikas, Der Aufschluss 25,577-591(1974)
    Portugal
     
    • Viana do Castelo District
      • Caminha
        • Arga de Baixo/Arga de Cima
    self-find. Pedro Alves collection
    • Viseu District
      • Mangualde
    Spain
     
    • Castile and Leon
      • Zamora
    USA
     
    • Arizona
      • Yavapai Co.
    Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 355; Jahns, Richard H. (1952), Pegmatite Deposits of the White Picacho District, Maricopa and Yavapai Counties, Arizona, Arizona Bureau of Mines Bull. 162.
          • Independence Gulch
    • California
      • San Diego Co.
        • Jacumba District
          • Mt. Tule
    Mineralogical Record 33(5):363-407
    • Maine
      • Oxford Co.
        • Greenwood
    No reference listed
    • North Carolina
      • Cleveland Co.
        • Kings Mountain District
    • South Dakota
      • Custer Co.
        • Custer District
          • Fourmile
    Moore, P. B. (1974) American Mineralogist: 59: 48-60.
      • Pennington Co.
        • Keystone District
          • Glendale
    Rocks & Minerals: 75(3): 156-169.
    Mineral and/or Locality
    Google
     
    www.mindat.org Web
    Copyright © Jolyon & Ida Ralph 1993-2008. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them.Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. If you would like to add information to improve the quality of our database, then click here to register.