What this is
collectible.web.id is a reference for mineral species: formula, classification, crystal system and elemental composition for every IMA-approved species we hold data for, alongside guides on identification, collecting and specimen care.
It is aimed at collectors who already know roughly what they are holding and want the numbers behind it, rather than at readers meeting minerals for the first time.
How the numbers are produced
Molar mass and elemental composition are calculated from the chemical formula rather than copied from anywhere. Where a formula contains a substitution group such as (Ca,Na), there is no single composition to calculate and the page says so instead of picking one.
Hardness and density are reported only where the source data carries them. Both are sparse, and a blank is more honest than an invented figure.
Photography
Specimen photographs come from Wikimedia Commons and are used under the licence each photographer chose — CC BY, CC BY-SA, CC0 or public domain. Every image carries its photographer and licence on the page it appears on.
If you are the photographer and an attribution is wrong, tell us and it will be corrected.
What this is not
It is not an authority. Mineral identification from a screen is not identification, and nothing here should be treated as a valuation or as advice on what to buy.
It is also not affiliated with any dealer, museum or rights holder.