Mindat Logo
Home Page Log In Message Board The Mindat Directory
Register Search Pages Mineral Chatroom The Mindat Store

Medaite

This page is currently not sponsored. Click here to sponsor this page.
Big Photo

Molinello Mine, Graveglia Valley, Ne, Genova Province, Liguria, Italy
© Stephan Wolfsried

Show Medaite Photos (14)



Formula:
(Mn,Ca)
 
6
(V,As)Si
 
5
O
 
18
OH
System:MonoclinicColour:Brownish-red
Name:For Dr. Francesco Meda, an amateur mineralogist from Turin.
This page provides mineralogical data about Medaite.

Classification of Medaite

IMA status:Approved
Strunz 8th edition ID:8/C.34-14
Nickel-Strunz 10th (pending) edition ID:9.BJ.30

9 : SILICATES (Germanates)
B : Sorosilicates
J : Sorosilicates with Si3O10, Si4O11, etc. anions; cations in octahedral [6] and greater coordination
Dana 8th edition ID:57.4.1.1

57 : SOROSILICATES Si3O10 Groups and Larger Noncyclic Groups
4 : Insular Si3O10 and Larger Noncyclic Groups with groups with 6 or more tetrahedra
Hey's CIM Ref.:17.7.5

17 : Silicates Containing other Anions
7 : Silicates with vanadate, arsenate or antimonate
mindat.org URL:http://www.mindat.org/min-2624.html
Please feel free to link to this page.

Type Occurrence of Medaite

Type Locality:Molinello Mine, Graveglia Valley, Ne, Genova Province, Liguria, Italy
Place of Conservation of Type Material:Institute of Mineralogy, Milan, Mineral Museums of Universities of Rome and Oslo, Norway.
Year of Discovery:1982
Geological Setting of type material:Manganese mine.

Physical Properties of Medaite

Lustre:Sub-Adamantine
Diaphaneity (Transparency):Translucent
Colour:Brownish-red
Cleavage:Distinct/Good
{100}
Parting:Distinct normal to elongation
Density (measured):3.65 - 3.75 g/cm3
Density (calculated):3.7 g/cm3

Crystallography of Medaite

Crystal System:Monoclinic
Cell Parameters:a = 6.71Å, b = 28.94Å, c = 7.57Å
β = 95.4°
Ratio:a:b:c = 0.232 : 1 : 0.262
Unit Cell Volume:V 1,463.47 ų (Calculated from Unit Cell)

Optical Data of Medaite

Type:Biaxial (+)
RI values: nα = 1.770 nβ = 1.780 nγ = 1.800
2V:Measured: 71° , Calculated: 72°
Maximum Birefringence:δ = 0.030

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Very High
Dispersion:r > v distinct
Pleochroism:Weak
Comments:Dark to lighter orange

Chemical Properties of Medaite

Formula:
(Mn,Ca)
 
6
(V,As)Si
 
5
O
 
18
OH
Essential elements:H, Mn, O, Si, V
All elements listed in formula:As, Ca, H, Mn, O, Si, V
Common Impurities:Fe,H2O

Relationship of Medaite to other Species

Related Minerals - Nickel-Strunz Grouping):

- +
9.BJ.05Orientite
Ca
 
2
Mn
2+
 
Mn
3+
2
(Si
 
3
O
 
10
)(OH)
 
4
9.BJ.10Rosenhahnite
HCa
 
3
[Si
 
3
O
 
9
(OH)]
9.BJ.15Trabzonite
Ca
 
4
(Si
 
3
O
 
10
) · 2H
 
2
O
9.BJ.20Thalénite-(Y)
Y
 
3
(Si
 
3
O
 
10
)(OH)
9.BJ.20Fluorthalénite-(Y)
Y
 
3
(Si
 
3
O
 
10
)F
9.BJ.25Tiragalloite
Mn
2+
4
(HAsSi
 
3
O
 
13
)
9.BJ.35Ruizite
Ca
 
2
Mn
3+
2
[(OH)
 
2
|H
 
2
Si
 
4
O
 
13
] · 2H
 
2
O
9.BJ.40Ardennite-(As)
Mn
2+
4
(Al,Mg)
 
6
(Si
 
3
O
 
10
)(SiO
 
4
)
 
2
(AsO
 
4
,VO
 
4
)(OH)
 
6
9.BJ.40Ardennite-(V)
Mn
2+
4
Al
 
4
(Mg,Al,Fe
3+
 
,Mn
3+
 
)
 
2
(Si
 
3
O
 
10
)(SiO
 
4
)
 
2
(VO
 
4
,SiO
 
4
)(OH)
 
6
9.BJ.45Kilchoanite
Ca
 
3
Si
 
2
O
 
7
9.BJ.50Kornerupine
Mg
 
3
Al
 
6
(Si,Al,B)
 
5
O
 
21
(OH)
9.BJ.50Prismatine
(◻,Fe,Mg)(Mg,Al,Fe)
 
5
Al
 
4
Si
 
2
(Si,Al)
 
2
(B,Si,Al)(O,OH,F)
 
22
9.BJ.55Zunyite
Al
 
13
Si
 
5
O
 
20
(OH,F)
 
18
Cl
9.BJ.60Hubeite
Ca
 
2
Mn
2+
 
Fe
3+
 
[HSi
 
4
O
 
13
] · 2H
 
2
O
9.BJ.65Cassagnaite
(Ca,Mn
2+
 
)
 
4
(Fe
3+
 
,Mn
3+
 
,Al)
 
4
(V
3+
 
,Mg,Al)
 
2
(Si
 
3
O
 
10
)(SiO
 
4
)
 
2
(OH,O)
 
8
Related Minerals - Hey's Index Grouping:

- +
17.7.1Suzukiite
BaVSi
 
2
O
 
7
17.7.2Franciscanite
Mn
2+
6
(V
5+
 
,☐)
 
2
(SiO
 
4
)
 
2
(O,OH)
 
6
17.7.3Kurumsakite
(Zn,Ni,Cu)
 
8
Al
 
8
V
5+
2
Si
 
5
O
 
35
 · 27H
 
2
O (?)
17.7.4Ardennite-(As)
Mn
2+
4
(Al,Mg)
 
6
(Si
 
3
O
 
10
)(SiO
 
4
)
 
2
(AsO
 
4
,VO
 
4
)(OH)
 
6
17.7.6Johninnesite
Na
 
2
Mn
2+
9
Mg
 
7
(OH)
 
8
[AsO
 
4
]
 
2
[Si
 
6
O
 
17
]
 
2
17.7.7Tiragalloite
Mn
2+
4
(HAsSi
 
3
O
 
13
)
17.7.8Dixenite
CuMn
2+
14
Fe
2+
 
(SiO
 
4
)
 
2
(As
5+
 
O
 
4
)(As
3+
 
O
 
3
)
 
5
(OH)
 
6
17.7.9Asbecasite
Ca
 
3
(Ti,Sn
4+
 
)Be
 
2
(AsO
 
3
)
 
6
(SiO
 
4
)
 
2
17.7.10Mcgovernite
Mn
 
19
Zn
 
3
(AsO
 
4
)
 
3
(AsO
 
3
)(SiO
 
4
)
 
3
(OH)
 
21
17.7.11Kraisslite
(Mn
2+
 
,Mg)
 
24
Zn
 
4
(SiO
 
4
)
 
8
(AsO
 
4
)
 
4
(OH)
 
12
17.7.12Schallerite
(Mn,Fe)
 
16
Si
 
12
As
 
3
O
 
36
(OH)
 
17
17.7.13Nelenite
(Mn,Fe)
 
16
(Si
 
12
O
 
30
)(OH)
 
14
[As
3+
3
O
 
6
(OH)
 
3
]
17.7.14Kolicite
Mn
2+
7
Zn
 
4
(AsO
 
4
)
 
2
(SiO
 
4
)
 
2
(OH)
 
8
17.7.15Yeatmanite
Zn
 
6
Mn
2+
9
Sb
5+
2
(SiO
 
4
)
 
4
O
 
12
17.7.16Welshite
Ca
 
4
Mg
 
9
Sb
 
3
O
 
4
[Si
 
6
Be
 
3
AlFe
 
2
O
 
36
]
17.7.17Katoptrite
(Mn
2+
 
,Mg)
 
13
(Al,Fe
3+
 
)
 
4
Sb
5+
2
(SiO
 
4
)
 
2
O
 
20
17.7.18Parwelite
Mn
 
10
Sb
 
2
As
 
2
Si
 
2
O
 
24
17.7.19Långbanite
(Mn
2+
 
,Ca)
 
4
(Mn
3+
 
,Fe
3+
 
)
 
9
Sb
5+
 
(SiO
 
4
)
 
2
O
 
16
17.7.20Chapmanite
Fe
3+
2
Sb
3+
 
(SiO
 
4
)
 
2
(OH)
17.7.21Cervandonite-(Ce)
(Ce,Nd,La)(Fe
3+
 
,Fe
2+
 
,Ti,Al)
 
3
O
 
2
(Si
 
2
O
 
7
)(As
3+
 
O
 
3
)(OH)

Other Names for Medaite

Synonyms:
IMA1979-062
Other Languages:
German:Medait
Russian:Медаит
Spanish:Medaita

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 Medaite

Reference List:

- +
American Mineralogist (1982): 67: 85-89.

Acta Crystallographica: 37: 1972-1978.

Nagashima, M. and Armbruster, T. (2010): Ardennite, tiragalloite and medaite: structural control of (As5+,V5+,Si4+)O4 tetrahedra in silicates. Mineralogical Magazine 74, 55-71

Internet Links for Medaite

Search Engines:
  • Look for Medaite on Google
  • Look for Medaite images on Google
    • External Links:
  • Look for Medaite on Webmineral
  • Look for Medaite on Athena Mineralogy
  • Look for Medaite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Medaite details from Handbook of Mineralogy (PDF)
    • Mineral Dealers:
  • Fine Minerals from Weinrich Minerals, Inc.
  • Rare and Unusual minerals at Mineralogical Research Company
  • Top quality minerals from Kristalle of California
  • High-end worldwide specimens & outstanding customer service
  • DAKOTA MATRIX offers Cabinet and Rare Species from Worldwide Localities.
  • Fabre Minerals - search for Medaite specimens
  • Search for Medaite from all mineral dealers at minfind.com
  • The Arkenstone - Fine Minerals
  • Wilensky Fine Minerals
  • webminerals
  • Buy from David K Joyce minerals
  • Mineral Classics - Worldwide Collector Quality Minerals and Gems
    • Specimens:The following Medaite specimens are currently listed for sale on minfind.com.
    Jobs:
  • Mining & Geology Jobs

    • Localities for Medaite

    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.
    Hide Locality List
    (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.
    Italy
     
    • Liguria
      • Genova Province
        • Ne
          • Graveglia Valley
    		Redazionale (2005): Sistematica ligure: resoconto 2005. Notiziario di Mineralogia del Ferrania Club, 19 , 3-5.
    [Amer.Min.(1982) 67, 85-89; MinRec 32:355]
            • Reppia
    		Rivista Mineralogica Italiana, (4), 131
    Switzerland
     
    • Grischun (Grisons; Graubünden)
      • Hinterrhein Valley
        • Ferrera Valley
          • Ausserferrera
    		J. Brugger et al.: Can. Mineral. 41:1423-1431 (2003); American Mineralogist: 91: 937-943.
    Mineral and/or Locality
    Search Google
     
    Copyright © Jolyon Ralph and Ida Chau 1993-2011. 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. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
    Current server date and time: 11th Sep 2011 20:37:51
    Mineral and Locality Search
    Mineral:
    and/or Locality:
    Options
    Fade toolbar when not in focusFix toolbar to bottom of page
    Hide Social Media Links
    Slideshow frame delay seconds