Home▸Geology & Earth Science▸Metamorphic Facies and Index Minerals

🪨 Metamorphic Facies and Index Minerals

Explore how rising temperature and pressure deep in the crust transform a parent rock into new mineral assemblages, and how geologists use metamorphic facies and index minerals to reconstruct a rock's buried history.

Geology & Earth Science3DModerate60 FPS🌍 Earth

The simulator demonstrates how a parent rock's mineral assemblage responds to changing temperature and pressure, showing the transition through metamorphic facies fields and the sequential appearance of index minerals such as chlorite, biotite, garnet, staurolite, kyanite, and sillimanite as conditions intensify.

🔬 What It Demonstrates

🎮 How to Use

Drag the temperature and pressure sliders, or click directly on the pressure-temperature diagram, to place a rock at a given set of conditions. Watch which metamorphic facies field is highlighted and which index minerals appear as stable, then trace different paths, such as a subduction-style high-pressure low-temperature route versus a regional collision-style balanced heating route, to compare the resulting mineral assemblages and facies sequences.

💡 Did You Know?

Did you know that the mineral kyanite and the mineral sillimanite are made of exactly the same atoms, aluminum, silicon, and oxygen, arranged into different crystal structures? Finding one instead of the other in a rock tells geologists precisely which side of a specific pressure-temperature boundary that rock experienced deep in the crust.

⚙ Under the hood

metamorphismpetrologymineralogygeologyindex mineralsmetamorphic faciesisogradstectonics

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install