Koskamo

Digital Gemology Gems MCP

This MCP server provides tools for identifying gemstones by comparing test readings (refractive index, birefringence, specific gravity, pleochroism, spectrum) against seven specific gemstones. It also offers detailed properties for each stone and comparison capabilities to distinguish between them.

Endpoint and access

No sign-in to connect and list tools. Individual tools may still need a vendor account, credentials, or permissions; check the documented prerequisites.

Digital Gemology Gems MCP logo, by Digital GemologyVendor evidenceStreamable HTTPNo sign-inEndpoint checked 2026-11-01Operated by Digital Gemology
MCP endpoint (Streamable HTTP)
https://digitalgemology.com/mcp/gems
Vendor documentation

What you can do with it

  • Identify a gemstone using refractive index and specific gravity readings
  • Compare two gemstones to see how they differ optically
  • Retrieve detailed optical properties like birefringence and dispersion
  • View absorption spectrum data for gem identification

Source and maintenance

Vendor evidenceRegistry 1.0.0
mcp-registry: com.digitalgemology/gem-identification@1.0.0Source repositoryProject website
Maintenance checked

Protocol and capabilities

Server
digital-gemology-gems 1.0.0
MCP protocol
2025-06-18
Tools
4 advertised
Resources
Not advertised
Resource templates
Not advertised
Prompts
Not advertised
Server-advertised capabilities
{
  "tools": {
    "listChanged": false
  }
}

Server-provided instructions

Untrusted server output shown for inspection. It is not Koskamo guidance and is excluded from knowledge search.

Gemological properties and identification for seven gemstones: diamond, moissanite, cubic zirconia, ruby, sapphire, emerald and amethyst, from the data behind Digital Gemology's free Refractometer, Dichroscope, Spectroscope and Polariscope. Use gem_properties for one stone's constants, pleochroism and spectrum, identify_gem to match readings (refractive index, birefringence, specific gravity, optic character, pleochroism, a spectrum line) against the seven, compare_gemstones for how to tell two of them apart (for example diamond or moissanite), and absorption_spectrum for what a hand spectroscope shows. Only these seven stones are covered: a match is a lead, not an identification, and a laboratory report is the proof. Link people to the stone's page and the free tool that shows the test.

Tools

4 advertised

gem_properties — Gemstone properties
Advertised by the server during the last successful anonymous check.
Advertised read-only

Everything Digital Gemology measures about one gemstone: refractive index (both rays for doubly refractive stones), birefringence, dispersion, specific gravity, hardness, crystal system, critical angle, what a refractometer, polariscope and dichroscope show, its pleochroic colors and the lines and bands a hand spectroscope shows, with links to the free tools.

gem_properties input schema
{
  "type": "object",
  "required": [
    "gemstone"
  ],
  "properties": {
    "gemstone": {
      "enum": [
        "diamond",
        "moissanite",
        "cubic-zirconia",
        "ruby",
        "sapphire",
        "emerald",
        "amethyst"
      ],
      "type": "string",
      "description": "Gemstone, as its slug."
    }
  },
  "additionalProperties": false
}
gem_properties annotations
{
  "title": "Gemstone properties",
  "readOnlyHint": true,
  "openWorldHint": false,
  "idempotentHint": true,
  "destructiveHint": false
}
identify_gem — Match gem test readings
Advertised by the server during the last successful anonymous check.
Advertised read-only

Match a stone's test readings against the seven gemstones Digital Gemology covers and rank them, saying which reading fits and which does not. Give any of: refractive index, birefringence, specific gravity, optic character, pleochroism, a spectrum line, or that the refractometer read over the limit. A match is a lead among seven stones only, not an identification.

identify_gem input schema
{
  "type": "object",
  "properties": {
    "pleochroism": {
      "enum": [
        "none",
        "weak",
        "distinct",
        "strong"
      ],
      "type": "string",
      "description": "What the dichroscope shows: none, weak, distinct or strong."
    },
    "birefringence": {
      "type": "number",
      "description": "The difference between the two readings, for example 0.008; 0 for a singly refractive stone."
    },
    "over_the_limit": {
      "type": "boolean",
      "description": "True if the refractometer showed no reading because the stone is above about 1.81."
    },
    "optic_character": {
      "enum": [
        "singly",
        "doubly"
      ],
      "type": "string",
      "description": "From the polariscope: singly refractive (stays dark) or doubly refractive (blinks light and dark)."
    },
    "refractive_index": {
      "type": "number",
      "description": "A refractometer reading, for example 1.765."
    },
    "specific_gravity": {
      "type": "number",
      "description": "Specific gravity, for example 4.0."
    },
    "spectrum_line_nm": {
      "type": "number",
      "description": "A line or band seen in a hand spectroscope, in nanometres, for example 694."
    }
  },
  "additionalProperties": false
}
identify_gem annotations
{
  "title": "Match gem test readings",
  "readOnlyHint": true,
  "openWorldHint": false,
  "idempotentHint": true,
  "destructiveHint": false
}
compare_gemstones — Tell two gemstones apart
Advertised by the server during the last successful anonymous check.
Advertised read-only

Two gemstones side by side, and the tests that tell them apart: refractive index, birefringence (doubling of back facets, polariscope), specific gravity, dispersion (fire), hardness, pleochroism and spectrum, each with the free tool that shows it. For questions like 'how do I tell diamond from moissanite?'.

compare_gemstones input schema
{
  "type": "object",
  "required": [
    "gemstone_a",
    "gemstone_b"
  ],
  "properties": {
    "gemstone_a": {
      "enum": [
        "diamond",
        "moissanite",
        "cubic-zirconia",
        "ruby",
        "sapphire",
        "emerald",
        "amethyst"
      ],
      "type": "string",
      "description": "The first gemstone, as its slug."
    },
    "gemstone_b": {
      "enum": [
        "diamond",
        "moissanite",
        "cubic-zirconia",
        "ruby",
        "sapphire",
        "emerald",
        "amethyst"
      ],
      "type": "string",
      "description": "The second gemstone, as its slug."
    }
  },
  "additionalProperties": false
}
compare_gemstones annotations
{
  "title": "Tell two gemstones apart",
  "readOnlyHint": true,
  "openWorldHint": false,
  "idempotentHint": true,
  "destructiveHint": false
}
absorption_spectrum — Absorption spectrum
Advertised by the server during the last successful anonymous check.
Advertised read-only

What a hand spectroscope shows for one gemstone: each absorption line and band with its position in nanometres, its cause (for example Cr3+ in ruby) and what it looks like, from Digital Gemology's Spectroscope.

absorption_spectrum input schema
{
  "type": "object",
  "required": [
    "gemstone"
  ],
  "properties": {
    "gemstone": {
      "enum": [
        "diamond",
        "moissanite",
        "cubic-zirconia",
        "ruby",
        "sapphire",
        "emerald",
        "amethyst"
      ],
      "type": "string",
      "description": "Gemstone, as its slug."
    }
  },
  "additionalProperties": false
}
absorption_spectrum annotations
{
  "title": "Absorption spectrum",
  "readOnlyHint": true,
  "openWorldHint": false,
  "idempotentHint": true,
  "destructiveHint": false
}

Prompts

Not advertised

No prompt definitions available.

Resources

Not advertised

No resource definitions available.

30-day availability

Aggregated from read-only remote checks; this is not a tool-execution or security guarantee.

Successful checks
1 of 1 (100%)
Average latency
268 ms
95th percentile latency
268 ms

Maintenance history

Public check and source-refresh events. Editorial and ownership records remain private.

  • · probe · passed · 268 ms · metadata changed · 4 tool(s)

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers the remote server. Use --scope project to write .mcp.json for the repo.
Claude Code configuration
claude mcp add --transport http digital-gemology-gems-mcp https://digitalgemology.com/mcp/gems

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).
Codex configuration
codex mcp add digital-gemology-gems-mcp --url https://digitalgemology.com/mcp/gems

Cursor

Merge this server into .cursor/mcp.json in your project, then enable digital-gemology-gems-mcp in your MCP settings.
Cursor configuration
{
  "mcpServers": {
    "digital-gemology-gems-mcp": {
      "url": "https://digitalgemology.com/mcp/gems"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure).
Cline configuration
{
  "mcpServers": {
    "digital-gemology-gems-mcp": {
      "type": "streamableHttp",
      "url": "https://digitalgemology.com/mcp/gems",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start digital-gemology-gems-mcp and inspect its tools.
VS Code configuration
{
  "servers": {
    "digital-gemology-gems-mcp": {
      "type": "http",
      "url": "https://digitalgemology.com/mcp/gems"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.
Gemini CLI configuration
gemini mcp add --transport http digital-gemology-gems-mcp https://digitalgemology.com/mcp/gems

Claude Desktop

Merge this into claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\), then restart Claude Desktop.
Claude Desktop configuration
{
  "mcpServers": {
    "digital-gemology-gems-mcp": {
      "url": "https://digitalgemology.com/mcp/gems"
    }
  }
}

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.
Windsurf configuration
{
  "mcpServers": {
    "digital-gemology-gems-mcp": {
      "serverUrl": "https://digitalgemology.com/mcp/gems"
    }
  }
}

Let your agent find its tools

Find servers like Digital Gemology Gems MCP from your agent. Add Koskamo once to search the index for endpoints, access requirements, and client setup. Public discovery needs no key.

Connect Koskamo Explore workflows
See all 4,664

Do you run Digital Gemology Gems MCP?

Prove ownership with a DNS record, a well-known file, or your Official MCP Registry entry, and your edits publish immediately. Proofs are re-checked weekly; admins can still hide or remove a listing.

Claim this listing