Allargentum Ag1-x Sbx x ≈ 0.09-0.16)
—
—
1
0
0
—
Mineral, Antimonide
Allophane Al2 O3 (SiO2 )1.3-2.0 ·2.5-3.0H2 O
Minerals containing H2O —
Open
Allophane from Kelly Mine, Magdalena District, Socorro County, New Mexico, USA
Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
0
9
0
PL
Mineral, Hydrated , Aluminosilicate
Almandine FeII 3 Al2 (SiO4 )3
Minerals containing SiO4 , Garnet —
Open
Garnet specimen from Idaho, USA
Photo by Chip Clark, via Smithsonian National Museum of Natural History
3
0
1
Reflectance
Mineral, Aluminosilicate
Alstonite BaCa(CO3 )2
Minerals containing CO3 —
Open
Specimen of alstonite from Brownley Hill Mine, Nenthead, Alston Moor District, North Pennines, Cumbria, England, UK
Photo by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
0
1
0
PL
Carbonate , Mineral
Altaite PbTe
Galena (group) —
1
0
0
—
Mineral
Alumina Al2 O3
—
Corundum
Open
Photograph of aluminium oxide
Photo by Ondřej Mangl, Public Domain
0
25
1
CL/SEM
Simple oxide , Synthetic , Compound
Aluminium Al
—
Steinhardtite
Open
CC-BY-SA 3.0, images-of-elements.com
1
6
2
SXES
Mineral, Element , Metal
Aluminium nitride AlN
—
—
0
20
0
CL, CL/SEM
Synthetic , Compound, Nitride
Aluminium orthophosphate AlPO4
—
Berlinite
Open
Synthetic Berlinite (AlPO4) crystals grown by a hydrothermal process
Photo by DMGualtieri, CC-BY-SA 3.0
1
2
0
PL/UV
Phosphate , Orthophosphate , Synthetic , Compound
Alunite KAl3 (SO4 )2 (OH)6
Minerals containing OH , Minerals containing SO4 —
Open
Alunite, massive material (Pen for scale) - Mineral collection of Brigham Young University Department of Geology, Provo, Utah - BYU index 10-7015
Photo by Andrew Silver, US Geological Survey. Public Domain
1
4
0
PL, Reflectance
Hydroxide , Mineral, Sulphate
Amazonite KAlSi3 O8
Microcline —
Open
Microcline (var. amazonite) and quartz, from Smoky Hawk claim, Crystal Peak area, Teller County, Colorado, USA. Size: 10.7 x 7.0 x 5.7 cm
Rob Lavinsky, iRocks.com – CC-BY-SA-3.0
0
7
0
PL, PL/XL
Aluminosilicate , Variety
Amber —
—
—
Open
Reflected light otical micrograph of cross section of amber in 'P-0431 Amber' standard (CSIRO) from Latvia (probably). Date: March 2026. Crossed polarisers.
Micrograph by Aaron Torpy. (C) 2026 CSIRO Mineral Resources. All rights reserved.
1
1
0
PL
Compound , Organic
Amblygonite LiAl(PO4 )F
Minerals containing PO4 , Amblygonite (group) —
Open
Faceted amblygonite gem, from Ceará, Brazil. Specimen M 36903, Museums Victoria.
Copyright Museums Victoria / CC BY (Licensed as Attribution 4.0 International)
4
4
1
Reflectance
Mineral, Phosphate , Orthophosphate
Amesite Mg2 Al(AlSiO5 )(OH)4 , Mg2 Al(SiAl)O5 (OH)4
Minerals containing OH , Serpentine (subgroup) —
Open
Amesite specimen from Chester, MA, USA
Photo by Burton Litman, via Smithsonian National Museum of Natural History
0
1
0
PL/XL
Hydroxide , Mineral, Aluminosilicate
Amethyst SiO2
Quartz —
Open
Amethyst from Guerrero, Mexico
Photo by Chip Clark, Smithsonian Institution. CC0
0
1
0
PL
Variety , Simple oxide
