Vitrinite reflectance

{
  "id": "MLC-T-OAG-004059",
  "term": "Vitrinite reflectance",
  "field": "Oil and gas",
  "definition": "The percentage of incident light reflected from polished vitrinite particles in a rock sample, measured under oil immersion at 546 nm, which rises irreversibly with burial temperature and so records the thermal maturity of organic matter. Values below about 0.6 percent indicate immature source rock, roughly 0.6 to 1.3 percent the oil window, and higher values the wet gas and dry gas stages.",
  "subject": "Geology",
  "url": "https://mlchart.com/terminology/oil-and-gas/vitrinite-reflectance/"
}