Ministry of Gems — Gemmology & Gemstones
Gemology & gemmology: 215 FGAA terms, 25 handbooks, live gem stock, signed passport verification.
Should I use this
Quality & Safety
Findings (1)
- LOWTool 'faceup_size_estimate' description lacks action verbin faceup_size_estimate
Based on automated analysis of tool definitions and protocol compliance.
Context Cost
This is the approximate number of tokens consumed each time the server's tools are loaded into a model's context. Higher counts reduce the attention available for other tasks.
Install
One-Click Install
Add this to your `claude_desktop_config.json` file:
{
"mcpServers": {
"gemmology": {
"url": "https://mog-concierge.33guruge.workers.dev/mcp"
}
}
}Remote endpoints
https://mog-concierge.33guruge.workers.dev/mcpstreamable-httpWhat it can do
Tool inventory
Tools (13)
🟢define_gem_term(term)
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.
Input Schema
{
"type": "object",
"properties": {
"term": {
"type": "string",
"description": "The gemmological term to define."
}
},
"required": [
"term"
]
}Output Schema
{
"type": "object",
"properties": {
"term": {
"type": "string",
"description": "Canonical term name."
},
"definition": {
"type": "string",
"description": "FGAA-verified definition."
},
"section": {
"type": "string",
"description": "Lexicon subject section."
},
"url": {
"type": "string",
"description": "Citable anchor URL on ministryofgems.com.au."
},
"verified_by": {
"type": "string",
"description": "Credential of the verifying gemmologist."
},
"source": {
"type": "string",
"description": "Name of the source work."
},
"found": {
"type": "boolean",
"description": "False when no term matched."
},
"message": {
"type": "string"
},
"hint": {
"type": "string"
},
"lexicon_url": {
"type": "string"
}
},
"description": "The verified definition, or found:false with a hint when no term matches."
}🟢search_gem_knowledge(query, limit)
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.
Input Schema
{
"type": "object",
"properties": {
"query": {
"type": "string",
"description": "Search query."
},
"limit": {
"type": "integer",
"description": "Max results (default 5, max 20)."
}
},
"required": [
"query"
]
}Output Schema
{
"type": "object",
"properties": {
"query": {
"type": "string",
"description": "The query as interpreted."
},
"result_count": {
"type": "integer"
},
"results": {
"type": "array",
"description": "Ranked matches.",
"items": {
"type": "object",
"properties": {
"score": {
"type": "number",
"description": "Relevance score. Not emitted; ordering conveys rank."
},
"type": {
"type": "string",
"description": "lexicon_term, handbook_section or handbook."
},
"title": {
"type": "string",
"description": "Lexicon term name, or the handbook title."
},
"section": {
"type": "string",
"description": "Lexicon subject section, or the handbook section heading."
},
"snippet": {
"type": "string",
"description": "Verbatim passage from the published text, centred on the match."
},
"url": {
"type": "string",
"description": "Citable URL, deep-linked to the chapter where possible."
}
}
}
},
"verified_by": {
"type": "string"
}
},
"required": [
"query",
"result_count",
"results"
]
}🟢list_gem_terms(section)
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.
Input Schema
{
"type": "object",
"properties": {
"section": {
"type": "string",
"description": "Optional section filter, e.g. \"Treatments & Enhancement\"."
}
}
}Output Schema
{
"type": "object",
"properties": {
"sections": {
"type": "array",
"items": {
"type": "string"
},
"description": "All lexicon section names."
},
"term_count": {
"type": "integer"
},
"terms": {
"type": "array",
"items": {
"type": "object",
"properties": {
"term": {
"type": "string"
},
"section": {
"type": "string"
},
"url": {
"type": "string"
}
}
}
}
},
"required": [
"sections",
"term_count",
"terms"
]
}🟢verify_gem_passport(stone_id)
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.
Input Schema
{
"type": "object",
"properties": {
"stone_id": {
"type": "string",
"description": "Stone ID as printed on the passport or product page, e.g. \"12322\", \"RUBY-B0797\", \"80067\"."
}
},
"required": [
"stone_id"
]
}Output Schema
{
"type": "object",
"properties": {
"found": {
"type": "boolean"
},
"verified": {
"type": "boolean",
"description": "True only when digest and signature both check out."
},
"stone_id": {
"type": "string"
},
"status": {
"type": "string"
},
"title": {
"type": "string"
},
"product_url": {
"type": "string"
},
"fingerprint": {
"type": "string"
},
"sha256": {
"type": "string"
},
"digest_matches": {
"type": "boolean"
},
"signature_valid": {
"type": "boolean"
},
"issued": {
"type": "string"
},
"record": {
"type": "object"
},
"corpus_url": {
"type": "string"
},
"register_url": {
"type": "string"
},
"note": {
"type": "string"
}
}
}🟢search_gem_inventory(query, type, min_carat, max_carat, min_price_aud, ...)
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.
Input Schema
{
"type": "object",
"properties": {
"query": {
"type": "string",
"description": "Free text, e.g. \"unheated ceylon blue sapphire\", \"australian opal pendant\", \"teal sapphire ring\"."
},
"type": {
"type": "string",
"description": "Optional: gems | ring | pendant | earrings | bracelet | jewellery."
},
"min_carat": {
"type": "number"
},
"max_carat": {
"type": "number"
},
"min_price_aud": {
"type": "number"
},
"max_price_aud": {
"type": "number"
},
"in_stock_only": {
"type": "boolean",
"description": "Default true."
},
"limit": {
"type": "integer",
"description": "Max results, default 8, max 25."
}
}
}Output Schema
{
"type": "object",
"properties": {
"query": {
"type": "string"
},
"result_count": {
"type": "integer"
},
"results": {
"type": "array",
"items": {
"type": "object",
"properties": {
"title": {
"type": "string"
},
"url": {
"type": "string"
},
"price_aud": {
"type": "number"
},
"available": {
"type": "boolean"
},
"carat": {
"type": "number"
},
"product_type": {
"type": "string"
},
"passport_url": {
"type": "string"
},
"stone_id": {
"type": "string"
},
"image": {
"type": "string"
}
}
}
},
"currency": {
"type": "string"
},
"catalogue_size": {
"type": "integer"
}
},
"required": [
"query",
"result_count",
"results"
]
}🟢sapphire_price_guide(origin, carat)
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.
Input Schema
{
"type": "object",
"properties": {
"origin": {
"type": "string",
"description": "Optional: \"Australian\" or \"Ceylon\"."
},
"carat": {
"type": "number",
"description": "Optional carat weight to select the matching band."
}
}
}Output Schema
{
"type": "object",
"properties": {
"as_of": {
"type": "string"
},
"currency": {
"type": "string"
},
"matched_bands": {
"type": "array",
"items": {
"type": "object"
}
},
"all_bands": {
"type": "array",
"items": {
"type": "object"
}
},
"source_url": {
"type": "string"
},
"basis": {
"type": "string"
},
"note": {
"type": "string"
}
}
}🟢gem_properties(species)
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.
Input Schema
{
"type": "object",
"properties": {
"species": {
"type": "string",
"description": "Species or trade name, e.g. \"sapphire\", \"diamond\", \"opal\"."
}
},
"required": [
"species"
]
}Output Schema
{
"type": "object",
"properties": {
"found": {
"type": "boolean"
},
"species": {
"type": "string"
},
"mohs_hardness": {
"type": "string"
},
"refractive_index": {
"type": "string"
},
"specific_gravity": {
"type": "string"
},
"birefringence": {
"type": "string"
},
"crystal_system": {
"type": "string"
},
"source_url": {
"type": "string"
},
"licence": {
"type": "string"
}
}
}🟢compare_gems(gem_a, gem_b)
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".
Input Schema
{
"type": "object",
"properties": {
"gem_a": {
"type": "string"
},
"gem_b": {
"type": "string"
}
},
"required": [
"gem_a",
"gem_b"
]
}Output Schema
{
"type": "object",
"properties": {
"found": {
"type": "boolean"
},
"a": {
"type": "object"
},
"b": {
"type": "object"
},
"harder": {
"type": "string"
},
"note": {
"type": "string"
}
}
}🟢birthstone_for_month(month)
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.
Input Schema
{
"type": "object",
"properties": {
"month": {
"type": "string",
"description": "\"September\", \"sep\" or \"9\"."
}
},
"required": [
"month"
]
}Output Schema
{
"type": "object",
"properties": {
"found": {
"type": "boolean"
},
"month": {
"type": "string"
},
"modern": {
"type": "string"
},
"traditional_or_alternative": {
"type": "string"
},
"handbook_url": {
"type": "string"
},
"source_url": {
"type": "string"
}
}
}🟢gem_care_guide(gemstone)
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.
Input Schema
{
"type": "object",
"properties": {
"gemstone": {
"type": "string"
}
},
"required": [
"gemstone"
]
}Output Schema
{
"type": "object",
"properties": {
"found": {
"type": "boolean"
},
"gemstone": {
"type": "string"
},
"warm_soapy_water": {
"type": "string"
},
"ultrasonic_cleaner": {
"type": "string"
},
"steam_cleaner": {
"type": "string"
},
"everyday_wear_notes": {
"type": "string"
},
"handbook_url": {
"type": "string"
},
"source_url": {
"type": "string"
}
}
}🟢get_gem_product(handle)
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.
Input Schema
{
"type": "object",
"properties": {
"handle": {
"type": "string",
"description": "Product handle (e.g. \"blue-australian-sapphire-1-47ct-oval-80062\") or full product URL."
}
},
"required": [
"handle"
]
}Output Schema
{
"type": "object",
"properties": {
"found": {
"type": "boolean"
},
"title": {
"type": "string"
},
"url": {
"type": "string"
},
"price_aud": {
"type": "number"
},
"available": {
"type": "boolean"
},
"specifications": {
"type": "object"
},
"description": {
"type": "string"
},
"images": {
"type": "array",
"items": {
"type": "string"
}
},
"variants": {
"type": "array",
"items": {
"type": "object"
}
},
"passport_url": {
"type": "string"
},
"stone_id": {
"type": "string"
},
"checkout_link": {
"type": "string"
},
"checked_at": {
"type": "string"
}
}
}🟢lab_report_check(lab, report_number)
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.
Input Schema
{
"type": "object",
"properties": {
"lab": {
"type": "string",
"description": "Laboratory name or acronym, e.g. \"GIA\", \"GRS\", \"SSEF\"."
},
"report_number": {
"type": "string"
}
},
"required": [
"lab"
]
}Output Schema
{
"type": "object",
"properties": {
"found": {
"type": "boolean"
},
"lab": {
"type": "string"
},
"report_number": {
"type": "string"
},
"verify_url": {
"type": "string"
},
"verifies_coloured_stones": {
"type": "boolean"
},
"checklist": {
"type": "array",
"items": {
"type": "string"
}
},
"lab_note": {
"type": "string"
},
"house_position": {
"type": "string"
},
"reminder": {
"type": "string"
}
}
}🟢faceup_size_estimate(species, shape, carat)
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.
Input Schema
{
"type": "object",
"properties": {
"species": {
"type": "string",
"description": "e.g. sapphire, diamond, spinel, emerald, opal (default diamond)."
},
"shape": {
"type": "string",
"description": "default round"
},
"carat": {
"type": "number"
}
},
"required": [
"carat"
]
}Output Schema
{
"type": "object",
"properties": {
"found": {
"type": "boolean"
},
"species": {
"type": "string"
},
"shape": {
"type": "string"
},
"carat": {
"type": "number"
},
"specific_gravity": {
"type": "number"
},
"approx_face_up_mm": {
"type": "object"
},
"display": {
"type": "string"
},
"diamond_equivalent_mm": {
"type": "string"
},
"method": {
"type": "string"
},
"note": {
"type": "string"
}
}
}Community
Evidence