Corrections, additions and identification questions are all welcome. This is a reference site, and a reference that is wrong is worse than no reference.
Write to [email protected]. Please put the subject of the sheet in the subject line — for example "slate: cleavage angle" or "about page: coverage". Mail sent to this address reaches the person who writes the sheets, not a support queue.
If a property in a sheet is wrong — a hardness, a cleavage angle, a streak colour, a locality, a hazard — say which sheet and what the correct value is, with a reference if you have one. Factual corrections are the highest value mail this site receives and they are actioned first.
We do not identify specimens from photographs, and the reason is not politeness. A photograph cannot tell anyone the hardness, the streak, the acid reaction or the heft, and those four tests carry most of the diagnostic information. If you send a question, include: where it was found, what rock it was in, its hardness against a knife and a coin, its streak colour on unglazed tile, whether it fizzes in dilute acid, whether a magnet affects it, and its approximate density relative to a similar-sized piece of quartz. With those six answers we can usually help. Without them, no one can.
The text and the generated plates on this site are ours. Short quotation with a link back is fine. Wholesale copying of sheets, or republishing them as your own reference, is not. If you want to use material for teaching, write and ask — requests from schools and clubs are normally granted.
Valuation of specimens or collections, identification of cut gemstones, advice on whether to buy a mineral specimen, and permission to collect at any particular site. Those questions belong to appraisers, gemmologists and the land managers respectively.