The 13th Akihabara Mineral Marche occupies Akihabara UDX 2F AKIBA_SQUARE from Friday 11 September through Sunday 13 September 2026. Admission is free. You do not book, and you do not sign a visitor sheet. Organiser Mineral Marche Co. lists about 100 dealers and about 200,000 mineral, fossil, meteorite, and jewellery pieces, billed as "Earth's treasures in AKB." Hours are Friday 12:00-21:00, Saturday 10:00-19:00, and Sunday 10:00-16:00. Last entry is 30 minutes before close. The structured listing lives on the event page. This is the floor walk: how to spend a few hours without buying junk or missing the Sunday cutoff.
Friday night is the quiet buying window
Most Tokyo gem fairs punch visitors on Saturday morning. This one is different because Friday runs until 21:00. If you work in Chiyoda, you can walk over after dinner, use the cloakroom, and still have three hours on the tables. UDX itself is a 3-minute walk from JR Akihabara Station's Electric Town Exit via Akihabara Bridge. Tokyo Metro Hibiya Line exit 3 is about 4 minutes. Ginza Line Suehirocho exit 1 is about 3 minutes. That Friday slot is also the only evening hours of the three days. Sunday dies at 16:00. If Sunday is your only free day, be inside by 11:00, not 15:00.
The hall is the same AKIBA_SQUARE used for anime pop-ups, so the lighting is exhibition-bright rather than jewellery-boutique dim. Stalls spill onto the half-outdoor terrace in front of the hall. Terrace stock is often cheaper specimens and leftover lots. Indoor tables hold the cut stones and the cases with locks. Ask before you photograph. Organisers say about 70 percent of shops allow photos if you speak first. About 90 percent take cards, but the remaining cash-only tables are usually the ones with the cheapest trays. Bring yen as well as a card.
What a few hundred yen actually buys versus a six-figure tray
The official line is "from a few hundred yen to several million yen." That is accurate, and it is also how people overspend. The cheap trays are tumbled quartz, small calcite, and dyed agate. Those are fine if you want a pocket stone. They are not Japanese locality pieces. If you want Japan-origin minerals, look for the domestic mineral corner and ask for the mine name before you pay. Dealers who list a locality on the card are easier to trust than dealers who only write a hardness number.
- Ishino Minoru and Mineral Adventure are the kind of tables where you can handle rough and ask for a locality without getting a sales script.
- Opal Direct / Gem Story and Pariba Tourmaline by iGems are cut-stone tables. Prices jump fast once the stone is calibrated.
- Joytec (jadeite) and Yagi Trading (jade) are specialist cases. Do not haggle like a flea market here.
- Curious, Crystal World, and Mineral Marche HQ sit in the middle: mixed specimens, jewellery, and magazine back issues nearby.
The cloakroom at reception is free. Use it. A 2kg amethyst geode is a miserable companion for the rest of Electric Town. There is also a mineral buy-back desk at reception. Appraisal takes about an hour. That desk is for people who already own stones, not for flipping something you just bought two aisles over. Monthly Mineral Marche magazine back issues sell for ¥100 while stocks last. Grab a copy if you collect Japanese dealer ads. It is the cheapest thing in the building that still tells you who is who.
The Okachimachi jewellery twin the same weekend
Mineral Marche's own page flags a simultaneous Okachimachi jewellery event the same three days. Jewellery Marche in Okachimachi (Panda Hiroba) runs Friday and Saturday 11:00-20:00 and Sunday 11:00-17:00, also free. It is one JR stop north of Akihabara on the Yamanote Line, or a 15-minute walk up Chuo-dori. If your goal is wearable jewellery rather than cabinet specimens, do Okachimachi first while you still have patience, then drop into UDX for fossils and rough. Do not try to "do both fully" on Sunday. UDX closes 16:00 and Okachimachi 17:00.
Pets are not allowed at UDX. Parking is UDX Parking under the building, paid. An ATM sits on UDX 1F. A virtual walkthrough of AKIBA_SQUARE is on the venue site if you want to see column spacing before you drag a suitcase. The UDX announcement on 12 August 2026 repeated the free-entry pitch and the 100-dealer / 200,000-piece numbers. Those numbers match the Mineral Marche event page. When a blog and the organiser disagree, use mineralshow.net.
A loop that still leaves time for Radio Kaikan
A practical half-day: Electric Town Exit, Akihabara Bridge, UDX 2F, cloakroom, one slow lap of the terrace, one slow lap of the hall, pay, reclaim bags, then Radio Kaikan or Yodobashi Akiba. Do not start at the far back wall. Start at the cloakroom so you know where it is when your hands are full. If a dealer quotes a price that feels theatrical, walk the next three tables and come back. Specimens repeat across this circuit. The rare things (named Japanese localities, meteorite slices with a certificate, jadeite with a lab slip) do not.
Official site: 13th Akihabara Mineral Marche. Venue note: UDX AKIBA SPACE, 12 August 2026.
Practical Details
- Dates: 11 September (Fri) to 13 September (Sun) 2026
- Time: Fri 12:00-21:00, Sat 10:00-19:00, Sun 10:00-16:00 (last entry 30 minutes before close)
- Venue: Akihabara UDX 2F AKIBA_SQUARE, 4-14-1 Sotokanda, Chiyoda-ku, Tokyo 101-0021
- Nearest station: JR Akihabara Station, Electric Town Exit, about 3 minutes via Akihabara Bridge
- Price: Free admission, no reservation. Specimens from a few hundred yen. Magazine back issues ¥100
- Website: mineralshow.net (Akihabara)
- Event page: 13th Akihabara Mineral Marche
