hardrock

{
  "id": "MLC-T-ENV-012849",
  "term": "hardrock",
  "field": "Environment",
  "definition": "Locatable minerals that are neither leasable minerals (oil, gas, coal, oil shale, phosphate, sodium, potassium, sulphur, asphalt, or gilsonite) nor saleable mineral materials (e.g. , common variety sand and gravel). Hardrock minerals include, but are not limited to, copper, lead, zinc, magnesium, nickel, tungsten, gold, silver, bentonite, barite, feldspar, fluorspar, and uranium. (BLM, 1999b) Usually refers to rock types or mining environments where the rocks are hard and strong and where blasting is needed to break them for effective mining.",
  "subject": "Land, waste and cleanup",
  "references": [
    "Abandoned Mine Lands (AML) Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/hardrock/"
}