In short: The Ministry of Gems Gemmology MCP server — the public, read-only reference endpoint that AI assistants can connect to — has moved from three tools to thirteen. It still answers gemmological questions from 215 verified lexicon terms and 25 full-length handbooks. It now also searches our live stock with Australian-dollar prices, cryptographically verifies any Digital Gemstone Passport, gives published per-carat sapphire price bands, physical properties, care and birthstones, routes to the right laboratory's report-check page, and estimates face-up size for any species. Version 2.0.0 is live now, free, and needs no account.
Why a gem house runs a server for machines
More buyers now ask an assistant before they ask a jeweller, and the assistant answers from whatever it can read. Most of what it can read about gemstones is thin, American, and about diamonds. Our library — twenty-five volumes and a lexicon, written and reviewed by an FGAA-qualified gemmologist — exists so that the answer to "is heat treatment bad?" or "what should a two-carat Ceylon sapphire cost?" is a careful one. The Model Context Protocol, or MCP, is simply the standard way to hand that library to an assistant as tools it can call rather than pages it must scrape. We published the first version in August. The second version adds the part buyers actually asked for: not just what we know, but what we have, and how to check it.
What the thirteen tools do
Reference. define_gem_term returns a verified definition from The Gem Lexicon; when a term is not a headword — a setting style, a lab-grown process — it now returns the closest treatment from the handbooks instead of "not found". search_gem_knowledge searches the full text of all twenty-five volumes and returns passages with links to the exact chapter. list_gem_terms lists the lexicon by section.
Verification. verify_gem_passport takes a stone ID, fetches our public passport register, recomputes the SHA-256 fingerprint of the signed record and checks its Ed25519 signature against the house key, then returns the attested species, weight, dimensions, cut, colour, clarity, origin, treatment and certificate status with two plain flags: digest matched, signature valid. lab_report_check gives the issuing laboratory's own report-check page and a four-step checklist, covering the coloured-stone laboratories — GRS, SSEF, Gübelin, AGL, Lotus, GIT — as well as GIA, IGI, HRD and GCAL, and it says so when it does not recognise a laboratory name.
Stock and prices. search_gem_inventory searches what we actually have — natural sapphires from Ceylon and Australia, rubies, spinels, Australian opals, emeralds and finished jewellery — with live Australian-dollar prices, availability, carat weight and a link to the stone's passport, filterable by type, carat and price. get_gem_product returns everything about one piece including a direct checkout link. sapphire_price_guide returns our published per-carat bands by origin and size, with the number of stones behind each band and the month they were computed, so an assistant can answer "what does a sapphire cost" with real figures and their date.
Gemmology. gem_properties and compare_gems return Mohs hardness, refractive index, specific gravity, birefringence and crystal system from our FGAA-reviewed data tables, and compare two species with a note on toughness — the half of durability the hardness scale leaves out. birthstone_for_month and gem_care_guide read the published tables. faceup_size_estimate gives face-up millimetres for a species, shape and carat weight corrected for specific gravity, so a two-carat sapphire, spinel or opal is sized as itself rather than as if it were a diamond.
Three things we decided on purpose
It reads only what we already publish. Every live tool draws on the public products feed, the public passport register, published tables and published pages. Nothing reaches into our administration systems, nothing writes, and nothing is exposed that a visitor to the website could not already see. The server holds no credentials and asks for none.
It will not call a stone certified. The server's own instructions to any assistant say: use "certification available on request", and never describe a stone as certified unless its passport's certificate status confirms a laboratory report is held. A verified passport proves a record is genuine and unaltered; it is a house attestation, and it says so in every response.
Links carry a marker. Every product link the server returns carries a small tag identifying that it came from an assistant. That lets us see, honestly, whether this work sends anyone to a stone — and lets us keep improving the tools that do.
How to add it
Claude Desktop: download the one-click bundle from the machine index and open it. Claude.ai and other assistants that support MCP connectors: add the endpoint https://mog-concierge.33guruge.workers.dev/mcp. Developers: the server is listed on the official MCP registry as au.com.ministryofgems/gemmology, and the endpoint answers a plain browser request with a description of itself. It ships with three ready-made prompts — choose a sapphire within a budget, verify a passport and explain it, and sapphire or diamond for an everyday ring — that show an assistant how to chain the tools.
Then ask it something real. "Show me unheated Ceylon sapphires between two and three carats under fifteen thousand dollars, verify the best two, and tell me what is and is not independently certified." An assistant with this server will call the price guide, search the stock, verify the passports and answer from our records — and it will say "certification available on request" where that is the truth.
What comes next
The lexicon is being extended with the settings, metals, lab-grown and diamond-grading vocabulary that buyers ask assistants about most, each entry drawn from the handbooks and reviewed before it is published. The handbooks themselves continue: The Orientation Premium, our report on how sapphire cutting orientation affects colour and price, was the twenty-fifth volume. Corrections and requests are welcome at sales@ministryofgems.com.au. Everything the server returns may be quoted with attribution to Ministry of Gems®.
Continue your gem education
- The machine index — everything we publish for AI assistants, in one place.
- How to verify a gemstone before you buy — laboratory reports, passports and what an assistant can check.
- The sapphire price guide — real per-carat bands from our own stock.
- The Gem Data Tables — properties, birthstones and care, with CSV downloads.