Coverage
What this site covers, and where it does not. We would rather tell you the gaps than let you assume there are none.
What is here
Minerals, the elements and compounds they are made of, the rocks they occur in, the alloys and materials made from them, the processes that do the making, and what all of it is used for.
- Elements 93
- Minerals 62
- Mineral varieties 17
- Rocks 24
- Compounds 20
- Alloys 32
- Materials 80
- Processes 44
- Objects 15
- Industries 10
- Events 8
- Places 10
- Deposit types 3
- Applications 29
Thinly covered
There is less here about these than about the rest, so if one of them is what you came for, expect a short answer.
Known limitations
- No photographs. There are no pictures anywhere on the site. If you need to see what something looks like, this is not the reference for it.
- Two sources cannot be used. Mindat and the IMA mineral lists publish no terms we have been able to read, so nothing here rests on either. See data sources.
- Not every chemical element has a page. The ones that do are the ones with a story beyond their numbers — where they are found, what they are used for, why they behave as they do. A bare properties table tells you very little, and there are periodic tables everywhere that do it better.
- Most figures rest on one or two sources. Where a figure has been confirmed against a second, independent reference, it says so beside the number; where it has not, the confidence shown beside it is lower for that reason.
- Nothing here is safety guidance. We hold back claims about hazards, handling and exposure rather than publish them unchecked. Do not rely on this site for safety decisions.