Collecting · Inherited collections

“I inherited a mineral collection” — what to do first

Do nothing irreversible for 30 days. Photograph every specimen with its label, keep labels with their stones, and check for four hazard groups before sorting.

First action Photograph specimen and label togetherDo not Separate a label from its stoneWhat carries value Locality, condition, provenanceHazard check Radioactive, asbestiform, arsenate, mercuryStorage 45–60% RH, 16–18 °C

Do nothing irreversible for 30 days. In the first 24 hours, photograph each mineral specimen beside its own label and keep the two together, because the locality on that label is a large part of what a collection is worth. Then check for four hazard groups before handling anything further.

In short

  • The single most destructive thing you can do is separate a specimen from its label, and it is also the easiest. Provenance is a large part of what makes a collection worth more than a box of rocks, and once a label is orphaned it cannot be reunited.
  • There is almost certainly no deadline. Minerals do not perish on a schedule. Unless the house is being cleared this week or the collection is somewhere damp, you have months. Anyone telling you to decide quickly is telling you something about themselves.
  • Check for four hazard groups before you sort. The Natural Sciences Collections Association names radioactive minerals, asbestiform minerals, arsenic and antimony minerals and mercury as the categories needing specific handling. This is the one step that genuinely comes first.
  • Most collections contain a few good pieces and a long tail. That is the normal shape and it is not a disappointment. The work is identifying which is which, and that is done by a specialist looking at the actual specimens, not from a photograph of a drawer.
  • We are frequently not the answer. If the collection is of local or scientific importance, a museum is the right destination. If it is bound up in probate, the executor decides, not you. If it contains radioactive material, a Radiation Protection Adviser comes before a dealer.
What to do in the next 24 hours, the next 7 days and the next 30
WindowDo thisDo not do this
First 24 hoursLeave everything where it is. Photograph each specimen with its label in the same frame. Photograph the drawers and cabinets as found, before anything movesDo not tip drawers out, do not put specimens in one box together, do not throw away any paper
First 7 daysCheck for the four hazard groups. Move anything damp somewhere dry. Find and keep every notebook, catalogue, index card and old letterDo not wash anything. Do not attempt to clean or improve a specimen. Do not sell the pieces that look best
First 30 daysGet an opinion on the collection as a whole from someone who handles this material. Ask the local museum whether any of it is of regional importanceDo not split the collection before it has been looked at. Do not accept a single offer for the good pieces only
After 30 daysDecide: keep, donate, sell as a whole, or sell in parts. All four are legitimate outcomesDo not let the decision be made by whoever arrived first
If the house must be cleared soonerPhotograph, box carefully with labels attached, and move it. Storage is cheap and reversibleDo not let a house clearance firm take it as general contents

Why the labels matter more than the minerals

This is the part that surprises people, so it is worth putting first. A mineral specimen with a full history — the mine, the level, the date, the collectors who owned it in between — is a documented object. The same stone with no paperwork is decorative material. The difference between those two things is large, and it is entirely destroyed by the reasonable-looking act of putting all the specimens in a box and all the little cards in an envelope.

Old labels also carry information that no longer exists anywhere else. A mine that closed in 1901 has no records; the label written by the collector who was there is the record. That is why museums accession labels alongside specimens and why an ex coll. attribution to a known collector adds weight — see our page on what the abbreviations on a mineral label mean.

The rule, and it is the only rule on this page that has no exceptions: a label never travels separately from its specimen. If a specimen has several labels from successive owners, keep all of them, in order. If a label has fallen off, photograph it in the drawer position where you found it before you move either.

If the specimens are in a cabinet with numbered drawers and there is a catalogue somewhere, the catalogue is the most valuable single object in the house. Find it before you find anything else.

The hazard check, and how to do it without a specialist

Mineral collections assembled over decades routinely contain material that would not be handled casually today, and the Natural Sciences Collections Association's guidance for museum collections names the groups explicitly. You are not being asked to identify minerals — you are being asked to spot four situations and stop.

Radioactive minerals. Guidance for institutions is that a collection should be checked with a Geiger counter, and that if radioactive specimens are present a Radiation Protection Adviser should be contacted. Look for the words uraninite, pitchblende, torbernite, autunite, carnotite, thorite or monazite on labels, and for bright yellow or green secondary crusts. Handle with gloves and a dust mask, minimise the time you spend holding them, and wash your hands. Our page on whether a mineral is radioactive goes into the detail.

Asbestiform minerals. Anything fibrous — fine, hair-like, silky fibres that can be teased apart. Do not handle, do not repack, do not vacuum near it. Local councils employ asbestos officers.

Arsenic and antimony minerals, and soluble lead minerals. Very common in British collections because the classic Cornish and Cumbrian localities are arsenate localities. Gloves, no dust, no eating nearby, wash afterwards. Worth knowing: galena is not toxic in the same way, because it is insoluble.

Mercury. Rare but serious. Native mercury seeps and gives off vapour; keep it lidded and open only in ventilated conditions.

Our page on toxic minerals in a collection covers the practical handling. None of this is a reason to panic about a collection that has sat in a spare room for forty years — it is a reason to wear gloves and not to sand anything.

When it is urgent, and when it is not

Almost never urgent. Minerals are geologically old and are not going to deteriorate over the few weeks it takes to think. Three situations genuinely do have a clock on them, and it is worth knowing which.

A damp environment is urgent. A garage, a cellar or an unheated outbuilding above 60% relative humidity will actively damage sulphides — above that figure pyrite reacts with atmospheric water to form iron sulphates and a weak sulphuric acid, and the acid then attacks the labels. Above 65%, mould grows. Moving boxes into a heated part of the house is a same-day job and it is free. See why pyrite crumbles.

A house clearance is urgent, because clearance firms price contents by volume and a mineral collection looks like heavy rubbish. If a date is fixed, box the collection with labels attached and move it to storage. That decision is cheap, quick and completely reversible, which is exactly what you want when you cannot yet make the real decision.

Probate can impose a real deadline, but the deadline is administrative, not physical, and it belongs to the executor. If you are not the executor, the disposal decision is not yours to make. If the estate needs a value, that is a valuation question rather than a sale question — see is my rock worth anything for what actually drives value.

Everything else — deciding whether to keep it, learning what is in it, choosing a destination — benefits from taking longer, and gets worse when rushed.

Your four real options, and who each one suits

Keep it. Underrated. A collection that stays together in a dry room costs nothing to own and can be understood slowly. If any part of you wants to, do this and revisit in a year. Read handling and storage and stop there.

Donate or offer it to a museum. The right answer when material has regional or scientific importance: local suites, mines that no longer exist, type-locality material, or anything with a documented nineteenth-century history. Approach the county or university museum with your photographs and your catalogue. Be prepared for a museum to decline or to want only part — they are constrained by storage and by collecting policy, and a refusal is not a verdict on quality.

Sell it as a whole. Simplest, fastest, and it keeps the collection and its documentation together. It will realise less per specimen than a piece-by-piece sale, and that discount is real and worth understanding rather than resenting: whoever buys it takes on the sorting, the storage and the risk on the long tail.

Sell it in parts. Realises the most on the good material and leaves you holding everything that does not sell. It also takes months and it breaks the collection up permanently. Choose this deliberately, not by default because someone offered to take “just the nice ones”.

What we do here is the second half of that last option, from the other side: we keep a wanted list of what individual collectors are looking for and match specimens to it. That means we are a good fit if a collection contains fine specimens from named classic localities, and a poor fit if it is largely unlabelled or largely decorative material — in which case a general auction house or a mineral show will serve you better. There is no catalogue here and no stock, so a conversation costs nothing and commits nothing. Sending photographs of a few drawers, with the labels legible, is enough for anyone competent to tell you which of the four options above you are actually choosing between.

Questions

How do I find out what an inherited mineral collection is worth?
Not from a photograph, and not from online listings of superficially similar stones. Value in mineral specimens is driven by locality, condition, crystal quality, size and provenance, roughly in that order, and two specimens of the same species can differ enormously. Get the collection looked at as a whole by someone who handles the material, and get a second opinion if the first is also an offer to buy. Our page on what makes a specimen valuable sets out the factors. We do not publish market rates for specimens.
Should I clean the specimens before showing them to anyone?
No. Cleaning is the most common way inherited collections lose value. Water damages some species outright, a brush destroys delicate habits permanently, and old dust is not what anyone is judging. More importantly, dirt is reversible and a cleaning mistake is not. Show the collection as found, and let whoever assesses it decide what, if anything, should be touched. See how to clean mineral specimens for why the risk is asymmetric.
Is it safe to keep an old mineral collection in the house?
Generally yes, with sensible handling. The categories that need care are set out in the Natural Sciences Collections Association's Care and Conservation of Geological Specimens, which names radioactive minerals, asbestiform minerals, arsenic and antimony minerals and mercury, and advises gloves and a dust mask for radioactive specimens because radon decay products attach to dust that can be inhaled. Keep specimens in closed boxes, do not create dust, wash your hands, and get anything radioactive or fibrous assessed before handling it further.
Nobody in the family wants it. Is throwing it away wrong?
It is not wrong, but it is usually premature and it is rarely the easiest option anyway — mineral collections are heavy and disposal is not free. Before that point, offer it to a local museum, a university geology department, a mineral or lapidary society, or a school. Any of these may take material that has no commercial value but real teaching value. Old labels in particular should not go in a skip: if nothing else survives, a museum may want the documentation on its own.
Someone has offered to take the collection off my hands for free. Should I accept?
Not until you know what is in it. A free-removal offer is sometimes a genuine kindness and sometimes a purchase at a price of zero, and you cannot tell which without an independent look. The cost of waiting a month is nothing; the cost of being wrong is permanent. If the offer is genuine it will still be there in four weeks, and anyone who says it will not has answered the question for you.