Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
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 ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic TimeExplore Fossils
Minerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch 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
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral QuizTime Machine
Photo SearchPhoto GalleriesSearch by ColorPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

UM2001-19-SiO:AlCaMgNa

A variety of Omphacite
This page is currently not sponsored. Click here to sponsor this page.
Formula:
(Na,Mg,Ca)(Mg,Al)Si2O6
Specific Gravity:
3.344 (Calculated)
Crystal System:
Monoclinic
Supposedly the Na analogue of omphacite, but under the current classification is just a variety of omphacite with Na>Ca.

As inclusions in diamonds, from alluvials.

EPMA data [wt%]:

Na2O 6.21
CaO 5.07
MgO 16.13
MnO 0.47
FeO 3.18
NiO 0.0
Al2O3 8.34
Cr2O3 3.14
TiO2 0.01
SiO2 57.07

total 99.63

This corresponds to (Na0.42Mg0.36Ca0.19Mn0.01)Σ0.99(Mg0.48Al0.35Cr0.09Fe3+0.07Fe2+0.02)Σ1.00Si2O6.


Hide all sections | Show all sections

Unique IdentifiersHide

Mindat ID:
54303 (as UM2001-19-SiO:AlCaMgNa)
2991 (as Omphacite)
Long-form identifier:
mindat:1:1:54303:3 (as UM2001-19-SiO:AlCaMgNa)
mindat:1:1:2991:5 (as Omphacite)

IMA Classification of UM2001-19-SiO:AlCaMgNaHide

IMA status notes:
Unnamed (probably invalid)

Physical Properties of UM2001-19-SiO:AlCaMgNaHide

Density:
3.344 g/cm3 (Calculated)

Chemistry of UM2001-19-SiO:AlCaMgNaHide

Mindat Formula:
(Na,Mg,Ca)(Mg,Al)Si2O6
Element Weights:
Element% weight
O48.128 %
Si28.161 %
Mg12.185 %
Na11.526 %

Calculated from ideal end-member formula.
O
Si
Mg
Na
Elements listed:
Al, Ca, Mg, Na, O, Si - search for minerals with similar chemistry

Crystallography of UM2001-19-SiO:AlCaMgNaHide

Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 9.587(4) Å, b = 8.699(6) Å, c = 5.247(4) Å
β = 108.33(4)°
Ratio:
a:b:c = 1.102 : 1 : 0.603
Unit Cell V:
415.38 ų (Calculated from Unit Cell)
Z:
4
Comment:
method: SCXR

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.

Internet Links for UM2001-19-SiO:AlCaMgNaHide

References for UM2001-19-SiO:AlCaMgNaHide

Localities for UM2001-19-SiO:AlCaMgNaHide

Showing 1 localities.

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.
Hide all sections | Show all sections

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and 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 (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Brazil
 
  • Mato Grosso
    • Juína
Hutchison et al. (2001) +1 other reference
Quick NavTopUnique IdentifiersIMA Classification Physical Properties Chemistry Crystallography Other InformationInternet Links References Localities Locality List
 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: September 3, 2026 05:33:29 Page updated: August 31, 2026 11:30:37
Go to top of page