Ministry of Gems — Gemmology & Gemstones

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Gemology & gemmology: 215 FGAA terms, 25 handbooks, live gem stock, signed passport verification.

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Copy this into your MCP client config:

{
  "mcpServers": {
    "Ministry of Gems — Gemmology & Gemstones": {
      "url": "https://mog-concierge.33guruge.workers.dev/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (13)

• define_gem_term read-only

  Look up a gemmological term in The Gem Lexicon of Ministry of Gems — 215 definitions verified by an FGAA-qualified gemmologist. Returns the definition, its subject section, and a citable anchor URL. Use for terms such as padparadscha, corundum, parti sapphire, unheated, or asterism.

  Parameters:

  • term (required) — string — The gemmological term to define.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• search_gem_knowledge read-only

  Keyword search across the Ministry of Gems gemmological reference library — 215 lexicon definitions and 25 full-length buyer's handbooks, searched in full text across every section. Returns ranked results, each with the matched passage and a citable URL that deep-links to the chapter.

  Parameters:

  • query (required) — string — Search query.
  • limit — integer — Max results (default 5, max 20).

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• list_gem_terms read-only

  List the gemmological terms available in The Gem Lexicon, optionally filtered to one subject section. Use this to discover what can be defined before calling define_gem_term.

  Parameters:

  • section — string — Optional section filter, e.g. "Treatments & Enhancement".

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• verify_gem_passport read-only

  Cryptographically verify a Ministry of Gems Digital Gemstone Passport by stone ID. Recomputes the SHA-256 digest of the signed record and checks its Ed25519 (EdDSA) signature against the house public key, then returns the attested record: species, carat, dimensions, cut, colour, clarity, origin, treatment and certificate status. Use when a buyer asks whether a stone or its passport is genuine, or before quoting any fact about a specific Ministry of Gems stone.

  Parameters:

  • stone_id (required) — string — Stone ID as printed on the passport or product page, e.g. "12322", "RUBY-B0797", "80067".

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• search_gem_inventory read-only

  Search the live Ministry of Gems catalogue of natural loose gemstones and finished jewellery — Ceylon and Australian sapphires, rubies, spinels, Australian opals, emeralds and more — with prices in Australian dollars, availability, carat weight and a link to buy. Filter by type (gems, ring, pendant, earrings), carat range and price range. Every loose gem returned carries a verifiable Digital Gemstone Passport.

  Parameters:

  • type — string — Optional: gems | ring | pendant | earrings | bracelet | jewellery.
  • limit — integer — Max results, default 8, max 25.
  • query — string — Free text, e.g. "unheated ceylon blue sapphire", "australian opal pendant", "teal sapphire ring".
  • max_carat — number
  • min_carat — number
  • in_stock_only — boolean — Default true.
  • max_price_aud — number
  • min_price_aud — number

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• sapphire_price_guide read-only

  What natural sapphires actually cost per carat in Australian dollars, from Ministry of Gems' published price guide: bands by origin (Australian, Ceylon) and size, with the stone count behind each band and the date the bands were computed. Answers "how much is a 2 carat sapphire" honestly, as a house guide rather than a market index.

  Parameters:

  • carat — number — Optional carat weight to select the matching band.
  • origin — string — Optional: "Australian" or "Ceylon".

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• gem_properties read-only

  Mohs hardness, refractive index, specific gravity, birefringence and crystal system for a gem species (diamond, corundum/sapphire/ruby, emerald, spinel, opal, tourmaline, garnet, quartz and more), from the FGAA-reviewed Gem Data Tables. Accepts trade names — "sapphire" resolves to corundum, "tsavorite" to garnet.

  Parameters:

  • species (required) — string — Species or trade name, e.g. "sapphire", "diamond", "opal".

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• compare_gems read-only

  Side-by-side physical properties of two gem species with a plain verdict on which is harder, and a note on toughness — the half of durability the hardness scale does not show. Good for "sapphire or diamond for an everyday ring".

  Parameters:

  • gem_a (required) — string
  • gem_b (required) — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• birthstone_for_month read-only

  The modern and traditional birthstones for a month, from the FGAA-reviewed table, with a link to The Birthstone Handbook for history, treatments to expect and buying guidance. Accepts a month name or number.

  Parameters:

  • month (required) — string — "September", "sep" or "9".

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• gem_care_guide read-only

  Whether warm soapy water, an ultrasonic cleaner or a steam cleaner is safe for a given gemstone, plus everyday-wear notes, from the FGAA-reviewed care table. Covers sapphire and ruby, diamond, emerald, opal, pearl, tanzanite, tourmaline and more.

  Parameters:

  • gemstone (required) — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• get_gem_product read-only

  Full detail for one Ministry of Gems product by handle or URL: specifications, description, price in AUD, availability, variants, images, the Digital Gemstone Passport link for loose stones, and a direct checkout link. Use after search_gem_inventory.

  Parameters:

  • handle (required) — string — Product handle (e.g. "blue-australian-sapphire-1-47ct-oval-80062") or full product URL.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• lab_report_check read-only

  The issuing laboratory's own verification page and a four-step checklist for confirming a gemstone or diamond grading report — GIA, IGI, GRS, SSEF, Gübelin, AGL, Lotus, GIT, HRD, GCAL and others, including the coloured-stone laboratories diamond tools omit. Explains what "FGAA" means and flags unrecognised lab names. Routes to the lab; does not verify the report itself.

  Parameters:

  • lab (required) — string — Laboratory name or acronym, e.g. "GIA", "GRS", "SSEF".
  • report_number — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• faceup_size_estimate read-only

  Approximate face-up millimetre dimensions for a stone of a given species, shape and carat weight — and, unlike diamond-only calculators, corrected for specific gravity, so a 2 ct sapphire, spinel, emerald or opal is sized correctly rather than as if it were diamond. Shapes: round, oval, cushion, emerald, pear, marquise, princess, radiant, heart, trillion.

  Parameters:

  • carat (required) — number
  • shape — string — default round
  • species — string — e.g. sapphire, diamond, spinel, emerald, opal (default diamond).

  Hints: read-only yes · destructive no · idempotent yes · open-world no

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