| Abernathyite | |
| Adamite | |
| Adelite | |
| Aerugite | |
| Agardite-(Ce) | |
| 'Agardite-(Dy)' | | (Dy,La)Cu | | [(OH) | | |(AsO | | ) | | ] · 3H | | O |
|
| Agardite-(La) | | (La,Ce)Cu | | [(OH) | | |(AsO | | ) | | ] · 3H | | O |
|
| 'Agardite-(Nd)' | | (Nd,La,Ce)Cu | | [(OH) | | |(AsO | | ) | | ] · 3H | | O |
|
| Agardite-(Y) | | (Y,Ca)Cu | | [(OH) | | |(AsO | | ,HAsO | | )|(AsO | | ) | | ] · 3H | | O |
|
| Akrochordite | |
| 'Aktashite' | |
| Alacránite | |
| Alarsite | |
| Algodonite | |
| Allactite | |
| Alloclasite | |
| Alumopharmacosiderite | |
| 'Ammonium-Uranospinite' | |
| Anduoite | |
| Andyrobertsite | |
| Angelellite | |
| Annabergite | |
| 'Antimonial Arsenic' | |
| 'Antimonian Claudetite' | |
| 'Antimonian Gersdorffite' | |
| Arakiite | | (Zn,Mn | | )(Mn | | ,Mg) | | (Fe | | ,Al) | | (AsO | | )(AsO | | ) | | (OH) | | |
|
| Ardennite-(As) | | Mn | | [(Al,Mg) | | ][(OH) | | |(AsO | | ,VO | | )|(SiO | | ) | | |Si | | O | | ] |
|
| 'Argentoalgodonite' | |
| 'Argentodomeykite' | |
| Argentotennantite | |
| Arhbarite | |
| 'Arite' | |
| Armangite | |
| 'Arsenargentite' | |
| 'Arsenatian Vanadinite' | |
| Arsenbrackebuschite | |
| Arsendescloizite | |
| 'Arsenian Renierite' | |
| Arsenic | |
| 'Arsenic Sulphide Glass No. 1' | |
| Arseniopleite | |
| Arseniosiderite | |
| 'Arsenmiargyrite' | |
| 'Arsennickeleisen' | |
| Arsenoclasite | |
| Arsenocrandallite | |
| Arsenoflorencite-(Ce) | |
| 'Arsenoflorencite-(La)' | |
| 'Arsenoflorencite-(Nd)' | |
| Arsenogorceixite | |