{
  "api": "rock-types",
  "title": "Rock Types",
  "description": "Common igneous, sedimentary, and metamorphic rocks and their uses.",
  "emoji": "🪨",
  "license": "GPL-2.0-or-later",
  "count": 20,
  "self": "https://gratisapi.com/api/rock-types/index",
  "endpoints": {
    "list": "https://gratisapi.com/api/rock-types/index",
    "item": "https://gratisapi.com/api/rock-types/{id}"
  },
  "fields": [
    "common_use",
    "description",
    "id",
    "name",
    "type"
  ],
  "results": [
    {
      "id": "granite",
      "name": "Granite",
      "type": "Igneous",
      "description": "Coarse-grained rock of quartz and feldspar formed from slowly cooled magma.",
      "common_use": "Countertops, monuments, and building facades.",
      "url": "https://gratisapi.com/api/rock-types/granite"
    },
    {
      "id": "basalt",
      "name": "Basalt",
      "type": "Igneous",
      "description": "Fine-grained, dark volcanic rock that makes up much of the ocean floor.",
      "common_use": "Road aggregate and crushed stone.",
      "url": "https://gratisapi.com/api/rock-types/basalt"
    },
    {
      "id": "obsidian",
      "name": "Obsidian",
      "type": "Igneous",
      "description": "Glassy black rock formed when lava cools too quickly to crystallize.",
      "common_use": "Cutting tools and jewelry.",
      "url": "https://gratisapi.com/api/rock-types/obsidian"
    },
    {
      "id": "pumice",
      "name": "Pumice",
      "type": "Igneous",
      "description": "Light, porous volcanic rock full of gas bubbles that can float on water.",
      "common_use": "Abrasives and lightweight concrete.",
      "url": "https://gratisapi.com/api/rock-types/pumice"
    },
    {
      "id": "gabbro",
      "name": "Gabbro",
      "type": "Igneous",
      "description": "Coarse-grained dark rock, the intrusive equivalent of basalt.",
      "common_use": "Crushed stone and dimension stone.",
      "url": "https://gratisapi.com/api/rock-types/gabbro"
    },
    {
      "id": "andesite",
      "name": "Andesite",
      "type": "Igneous",
      "description": "Fine-grained volcanic rock common in continental arc volcanoes.",
      "common_use": "Construction aggregate.",
      "url": "https://gratisapi.com/api/rock-types/andesite"
    },
    {
      "id": "sandstone",
      "name": "Sandstone",
      "type": "Sedimentary",
      "description": "Rock made of cemented sand-sized grains, often quartz.",
      "common_use": "Building stone and paving.",
      "url": "https://gratisapi.com/api/rock-types/sandstone"
    },
    {
      "id": "limestone",
      "name": "Limestone",
      "type": "Sedimentary",
      "description": "Rock composed mainly of calcium carbonate from shells and marine debris.",
      "common_use": "Cement production and building stone.",
      "url": "https://gratisapi.com/api/rock-types/limestone"
    },
    {
      "id": "shale",
      "name": "Shale",
      "type": "Sedimentary",
      "description": "Fine-grained rock formed from compacted mud and clay that splits in layers.",
      "common_use": "Brick and ceramic manufacture.",
      "url": "https://gratisapi.com/api/rock-types/shale"
    },
    {
      "id": "conglomerate",
      "name": "Conglomerate",
      "type": "Sedimentary",
      "description": "Rock of rounded gravel and pebbles cemented together.",
      "common_use": "Decorative stone and aggregate.",
      "url": "https://gratisapi.com/api/rock-types/conglomerate"
    },
    {
      "id": "chalk",
      "name": "Chalk",
      "type": "Sedimentary",
      "description": "Soft white limestone made of microscopic marine plankton skeletons.",
      "common_use": "Writing chalk and lime.",
      "url": "https://gratisapi.com/api/rock-types/chalk"
    },
    {
      "id": "coal",
      "name": "Coal",
      "type": "Sedimentary",
      "description": "Combustible black rock formed from compressed ancient plant matter.",
      "common_use": "Fuel and electricity generation.",
      "url": "https://gratisapi.com/api/rock-types/coal"
    },
    {
      "id": "breccia",
      "name": "Breccia",
      "type": "Sedimentary",
      "description": "Rock of angular, broken fragments cemented in a fine matrix.",
      "common_use": "Decorative and ornamental stone.",
      "url": "https://gratisapi.com/api/rock-types/breccia"
    },
    {
      "id": "marble",
      "name": "Marble",
      "type": "Metamorphic",
      "description": "Recrystallized limestone prized for its color and smooth texture.",
      "common_use": "Sculpture, flooring, and countertops.",
      "url": "https://gratisapi.com/api/rock-types/marble"
    },
    {
      "id": "slate",
      "name": "Slate",
      "type": "Metamorphic",
      "description": "Fine-grained rock derived from shale that splits into thin flat sheets.",
      "common_use": "Roofing tiles and flooring.",
      "url": "https://gratisapi.com/api/rock-types/slate"
    },
    {
      "id": "gneiss",
      "name": "Gneiss",
      "type": "Metamorphic",
      "description": "Banded rock with alternating light and dark mineral layers.",
      "common_use": "Building stone and aggregate.",
      "url": "https://gratisapi.com/api/rock-types/gneiss"
    },
    {
      "id": "schist",
      "name": "Schist",
      "type": "Metamorphic",
      "description": "Foliated rock with visible platy minerals like mica that reflect light.",
      "common_use": "Decorative stone.",
      "url": "https://gratisapi.com/api/rock-types/schist"
    },
    {
      "id": "quartzite",
      "name": "Quartzite",
      "type": "Metamorphic",
      "description": "Very hard rock formed from metamorphosed quartz sandstone.",
      "common_use": "Countertops and railway ballast.",
      "url": "https://gratisapi.com/api/rock-types/quartzite"
    },
    {
      "id": "phyllite",
      "name": "Phyllite",
      "type": "Metamorphic",
      "description": "Foliated rock between slate and schist with a silky sheen.",
      "common_use": "Decorative and building stone.",
      "url": "https://gratisapi.com/api/rock-types/phyllite"
    },
    {
      "id": "anthracite",
      "name": "Anthracite",
      "type": "Metamorphic",
      "description": "The hardest, highest-carbon form of coal, formed under heat and pressure.",
      "common_use": "High-grade fuel.",
      "url": "https://gratisapi.com/api/rock-types/anthracite"
    }
  ]
}