The question
When someone inherits coins and searches for what to do, what do they find? We asked two narrow questions. First, what do the pages that rank for the main searches claim about the value lost to cleaning, which home methods they present, whether they advise checking sold listings, and whether the site offers to buy? Second, what do replies in public heirs’ threads actually say about cleaning, value, sold listings, and selling risks?
Headline counts
- 10 of 20 ranking pages put a percentage or money figure on what cleaning costs a coin; 1 of those 10 says how its figure was derived.
- 1 of 20 ranking pages tells readers to check sold listings. In heirs’ threads, the top three replies pointed to sold listings or auction records in 22 of 250 (8.8%).
- Cleaning came up in 30 of 250 heirs’ threads (12.0%). None of the 250 top replies endorsed abrasive or household cleaning; the 3 that said cleaning was OK described an acetone soak or water rinse without rubbing.
Coded by SellingCollectibles against a pre-registered scheme; one coder; intra-coder re-check of 15% of threads (38 of 250) with 97% agreement across coded fields (369 of 380 field codes).
Sample A: pages that rank for five searches
- Searches: should I clean old coins; does cleaning coins decrease value; what to do with an inherited coin collection; how to sell an inherited coin collection; how to clean old coins.
- Result lists: collected October 8, 2026 with a web search tool. They approximate Google’s results; they are not Google’s live, personalized US order.
- Inclusion rule: the top four distinct pages for each search (20 pages, 18 domains), with a fixed replacement rule for duplicates, dead pages, block pages, forums, encyclopedias, and non-English pages. No replacement was needed.
- Fetch: every page was re-fetched and read on October 8, 2026, and coded only from that day’s text.
- Codes: a numeric loss claim (a percentage or money example; words like “lose value” do not count); whether the claim names a source or explains its derivation, cites a named expert only, or neither; which cleaning methods it presents as usable; agreement with U.S. Mint, NGC, and American Numismatic Association guidance; sold-listing advice; an offer-to-buy call to action in the page content from a site that buys coins; and whether a named person appears as author, reviewer, or expert.
- Agreement scale: “Agrees” means the main advice for a coin of possible collector value is not to clean it, and the page presents no vinegar, baking soda, dip, or polish method (mild soap and water alone is consistent with the U.S. Mint). “Partly” means it cautions against cleaning valuable coins but also presents one of those methods.
Ranking-page results (N = 20)
| Measure | Pages |
|---|---|
| Operator: dealer or bullion seller / publisher / government / association | 11 / 7 / 1 / 1 |
| States a percentage or money figure for value lost to cleaning | 10 of 20 |
| …explains where the figure comes from | 1 of 10 |
| …attributes it to a named expert without data | 2 of 10 |
| …gives no source | 7 of 10 |
| Stated range reaches 90% | 6 of 20 |
| Presents any cleaning method as usable (including mild soap and water) | 5 of 20 |
| Presents vinegar, baking soda, a dip, or polish as usable | 3 of 20 |
| Agrees / partly agrees / disagrees with U.S. Mint, NGC, and ANA guidance / no cleaning advice | 16 / 3 / 0 / 1 |
| Recommends checking sold listings or prices realized | 1 of 20 |
| Offer-to-buy call to action in the page content | 7 of 20 (9 of 20 counting header links) |
| …among dealer pages | 7 of 11 |
| Names a person as author, reviewer, or expert | 10 of 20 |
With 20 pages, we report counts, not percentages. The percentage ranges below are the pages’ own claims; we did not test them.
Codes by page
| Page | Search | Operator | Loss stated | Source for figure | Methods presented as usable | Mint/NGC/ANA | Sold-listing advice | Offer to buy | Named person |
|---|---|---|---|---|---|---|---|---|---|
| bullionbypost.co.uk | Q1 | Dealer or bullion seller | — | — | — | Agrees | No | No | No |
| usmint.gov | Q1 | Government | — | — | Mild soap and water | Agrees | No | No | No |
| wikihow.com | Q1 | Publisher | 90% (expert quote) | Named expert, no data | Vinegar, ketchup, vegetable oil, baking soda, soap and water | Partly | No | No | Yes |
| trycoinidentifier.com | Q1 | Publisher | 20–90% | None given | Soap and water (also acetone) | Agrees | No | No | No |
| uscoinsguide.com | Q2 | Publisher | 10–30% (also: rarely worth more than half) | None given | — | Agrees | No | No | Yes |
| readingroom.money.org | Q2 | Association | 50% or more; up to 90% in extreme cases | None given | — | Agrees | No | No | Yes |
| tylergoldandbullion.com | Q2 | Dealer or bullion seller | — | — | — | Agrees | No | Yes | No |
| herobullion.com | Q2 | Dealer or bullion seller | 20–50%; up to 50–80% | None given | — | Agrees | No | No | Yes |
| jmbullion.com | Q3 | Dealer or bullion seller | — | — | — | Agrees | No | No (header link only) | No |
| clemsoncoinsandcurrency.com | Q3 | Dealer or bullion seller | 50–90% or more | None given | — | Agrees | No | Yes | No |
| usgoldandcoin.com | Q3 | Dealer or bullion seller | 50–90% | None given | — | Agrees | No | Yes | No |
| numisteria.com | Q3 | Publisher | — | — | — | Agrees | Yes | No | Yes |
| uscoinshows.com | Q4 | Publisher | 30–60% or more | None given | — | Agrees | No | No | Yes |
| pgsgoldandcoin.com | Q4 | Dealer or bullion seller | — | — | — | Agrees | No | Yes | Yes |
| atlantagoldandcoin.com | Q4 | Dealer or bullion seller | — | — | — | No cleaning advice | No | Yes | No |
| lonestarcoins.com | Q4 | Dealer or bullion seller | — | — | — | Agrees | No | Yes | No |
| wikihow.com | Q5 | Publisher | 90% (expert quote) | Named expert, no data | Soap and water, baking soda | Partly | No | No | Yes |
| mycoinage.co.uk | Q5 | Dealer or bullion seller | 30–70% | Says it is derived from auction sales | — | Agrees | No | No (header link only) | Yes |
| mvcoinshop.com | Q5 | Dealer or bullion seller | — | — | Soap and water, olive oil, acetone, baking soda with foil | Partly | No | Yes | No |
| uscoinsguide.com | Q5 | Publisher | — | — | — | Agrees | No | No | Yes |
Search key: Q1 should I clean old coins; Q2 does cleaning coins decrease value; Q3 inherited coin collection, what to do; Q4 how to sell an inherited coin collection; Q5 how to clean old coins. Two domains have two pages each (wikihow.com: Q1 and Q5; uscoinsguide.com: Q2 and Q5). Codes describe each page as fetched on October 8, 2026, and pages can change. The table scrolls sideways on small screens.
Sample B: heirs’ threads on Reddit
- Where: public posts in r/coins, r/coincollecting, and r/Numismatics, read through Reddit’s API in read-only mode. We did not post, vote, or message anyone, and we stored no usernames.
- Window: the 12 months before October 8, 2026. Included threads were posted October 11, 2025 to October 5, 2026 and read on October 8, 2026.
- Frame: two relevance-sorted searches per subreddit, one for inheritance words and one for relative and estate words. That gave 621 unique posts; 571 passed a title screen for coins that came from a relative or an estate.
- Sampling: the eligible list was shuffled with a fixed random seed (2026100802) and coded in that order until 250 threads were included.
- Coded and excluded: 298 threads coded; 250 included. 17 were excluded because they had no substantive reply, and 31 because they were not heirs’ threads on reading (for example, the coins were bought). None were removed or deleted. By subreddit, included / no reply / not an heir thread: r/coins 131 / 5 / 8; r/coincollecting 81 / 2 / 7; r/Numismatics 38 / 10 / 16.
- Post text: the post was available for every coded thread. Many are photo or video posts with little or no text, and they were coded from the title, any text, and the replies.
- What was coded: the title, the post, and the first three substantive replies under Reddit’s “top” sort. Bots, the poster’s own comments, removed comments, and reaction-only or joke-only replies were skipped.
Thread results (N = 250)
Counts with Wilson 95% intervals. Percentages are shown only where the group has 50 or more threads, so r/Numismatics (38) shows counts and intervals only.
| Measure | All threads (250) | r/coins (131) | r/coincollecting (81) | r/Numismatics (38) |
|---|---|---|---|---|
| Cleaning came up at all (title, post, poster, or any of the top three replies) | 30 of 250 12.0% (8.5–16.6%) | 17 of 131 13.0% (8.3–19.8%) | 8 of 81 9.9% (5.1–18.3%) | 5 of 38 interval 5.8–27.3% |
| The poster asked whether or how to clean | 6 of 250 2.4% (1.1–5.1%) | 3 of 131 2.3% (0.8–6.5%) | 2 of 81 2.5% (0.7–8.6%) | 1 of 38 interval 0.5–13.5% |
| The coins were described as already cleaned (by the poster or the top reply) | 7 of 250 2.8% (1.4–5.7%) | 4 of 131 3.1% (1.2–7.6%) | 0 of 81 0.0% (0.0–4.5%) | 3 of 38 interval 2.7–20.8% |
| Top reply: do not clean | 6 of 250 2.4% (1.1–5.1%) | 4 of 131 3.1% (1.2–7.6%) | 0 of 81 0.0% (0.0–4.5%) | 2 of 38 interval 1.5–17.3% |
| Top reply: cleaning is OK (all were conservation-style: acetone soak or water rinse, no rubbing) | 3 of 250 1.2% (0.4–3.5%) | 1 of 131 0.8% (0.1–4.2%) | 2 of 81 2.5% (0.7–8.6%) | 0 of 38 interval 0.0–9.2% |
| Top reply: worth face value, metal value, or “not much” | 80 of 250 32.0% (26.5–38.0%) | 46 of 131 35.1% (27.5–43.6%) | 28 of 81 34.6% (25.1–45.4%) | 6 of 38 interval 7.4–30.4% |
| Top reply: collector value, grading, or see a dealer or appraiser | 35 of 250 14.0% (10.2–18.8%) | 16 of 131 12.2% (7.7–18.9%) | 13 of 81 16.0% (9.6–25.5%) | 6 of 38 interval 7.4–30.4% |
| Top reply: identification only | 51 of 250 20.4% (15.9–25.8%) | 23 of 131 17.6% (12.0–25.0%) | 15 of 81 18.5% (11.6–28.3%) | 13 of 38 interval 21.2–50.1% |
| Top reply: something else (keep it, research it, storage, and similar) | 75 of 250 30.0% (24.7–35.9%) | 41 of 131 31.3% (24.0–39.7%) | 23 of 81 28.4% (19.7–39.0%) | 11 of 38 interval 17.0–44.8% |
| Any top-three reply framed value as face, metal value, or “not much” | 128 of 250 51.2% (45.0–57.3%) | 67 of 131 51.1% (42.7–59.5%) | 50 of 81 61.7% (50.8–71.6%) | 11 of 38 interval 17.0–44.8% |
| Any top-three reply suggested grading, a dealer, coin shop, appraiser, or a reference book or price guide | 89 of 250 35.6% (29.9–41.7%) | 43 of 131 32.8% (25.4–41.3%) | 32 of 81 39.5% (29.6–50.4%) | 14 of 38 interval 23.4–52.7% |
| Any top-three reply pointed to sold listings or auction records | 22 of 250 8.8% (5.9–13.0%) | 11 of 131 8.4% (4.8–14.4%) | 5 of 81 6.2% (2.7–13.6%) | 6 of 38 interval 7.4–30.4% |
| Any top-three reply warned about pawn or jewelry counters, offers below metal value or called lowball, strangers offering to buy by message, or scammers | 20 of 250 8.0% (5.2–12.0%) | 13 of 131 9.9% (5.9–16.2%) | 5 of 81 6.2% (2.7–13.6%) | 2 of 38 interval 1.5–17.3% |
Among the 30 threads where cleaning came up, the top reply said not to clean in 6 of 30 (interval 9.5–37.3%).
Reliability
Coded by SellingCollectibles against a pre-registered scheme; one coder; intra-coder re-check of 15% (38 of 250 threads) with 97% agreement across coded fields. The 38 threads were drawn with a second fixed seed (2026100803), fetched again, and re-coded without looking at the first codes. The re-check measures one coder’s consistency, not agreement between independent coders. It was done the same day, minutes to about half an hour after first coding, so it is likely optimistic. The ranking-page audit was not re-coded; its codes are mostly literal (whether a number, method, or offer appears on the page).
| Field | Same code on re-check | Cohen’s kappa |
|---|---|---|
| Top-reply type | 34 of 38 | 0.86 |
| Face or metal value framing | 33 of 38 | 0.73 |
| Grading, dealer, or reference suggested | 38 of 38 | 1.00 |
| Sold listings or auction records | 38 of 38 | 1.00 |
| Scam or lowball warning | 38 of 38 | 1.00 |
| Cleaning came up | 38 of 38 | 1.00 |
| Already cleaned | 38 of 38 | not defined (every re-checked thread had the same value) |
One of the 38 threads changed inclusion status on re-check. The published counts use the first-pass codes, as pre-registered.
Both coding schemes were written and fingerprinted (SHA-256) before any page was fetched or any thread was coded: the audit scheme at 9:55 a.m. CT and the Reddit plan at 9:55 a.m. CT on October 8, 2026 (fingerprints beginning 24664ad562bb and d8851812eb51). Later clarifications are dated in an internal change log.
Limits
- One coder. Every page and thread was coded by the same single coder. No second coder checked the work.
- Search-ranking bias. Sample A is the top of the results for five searches on one day, and rankings change.
- Approximate search results. The result lists came from a web search tool that approximates Google, not from Google’s live US results.
- Subreddit skew. Reddit replies lean toward collectors and reflect each subreddit’s culture. r/coins is about half the sample (131 of 250), heirs who post publicly may differ from those who do not, and relevance-sorted search does not return every heir thread.
- Metal-price context. Many replies framed value as metal value while precious-metal prices were high, so that framing may follow the market.
- Small groups. r/Numismatics has 38 threads, and its intervals are wide.
- What the codes mean. The codes record what pages and replies said, not whether the advice was right.
Refresh plan
Every six months, next in April 2027: re-run the five searches, re-fetch and re-code the top four pages for each with the same scheme, draw a new 250-thread sample from the following 12 months, re-check 15% of threads, and record what changed below. Any change to the scheme will be fingerprinted before coding and listed here.
Change log
- October 8, 2026: first publication. Sample A: 20 pages fetched October 8, 2026. Sample B: 250 threads posted October 11, 2025 to October 5, 2026.
Coded by SellingCollectibles against a pre-registered scheme; one coder; intra-coder re-check of 15% of threads (38 of 250). Only aggregate counts are published here: no quotes, usernames, post links, or per-post data from Reddit. This is a count of what pages and replies said, not an appraisal, price guide, or claim that any coin has market value. The publisher is responsible for it under the editorial standard.