OBSIDIAN (Volcanic Silica Glass) | |
OKENITE (Hydrated Calcium Silicate) | |
OLIGOCLASE (Sodium Calcium Aluminum Silicate) | |
* | OLIVINE (Group) |
OLIVINE (Magnesium Iron Silicate) | |
OLIVENITE (Copper Arsenate Hydroxide) | |
0 | ONYX (variety of Quartz - Silicon Oxide) |
OPAL (Hydrated Silica) | |
* | ORGANICS (Class) |
ORPIMENT (Arsenic Sulfide) | |
ORTHOCLASE (Potasium Aluminum Silicate) | |
0 | OSBORNITE (Titanium Nitride) |
OSUMILITE (Hydrated Potassium Sodium Iron Magnesium Aluminum Silicate) | |
0 | OTAVITE (Cadmium Carbonate) |
* | OXIDES (Class) |