The Field Description Of Igneous Rocks Here

Distinguish between the fresh surface (broken with a hammer) and the weathered surface . Weathering can hide the rock's true color or highlight certain mineral textures. 2. Texture (The Cooling History) Texture is the most critical diagnostic feature:

Identify the minerals present and estimate their relative abundance: The Field Description of Igneous Rocks

Note patterns like columnar jointing (hexagonal columns) or cooling cracks. Distinguish between the fresh surface (broken with a

Fragmental texture (bits of ash, pumice, or rock fragments from explosive eruptions). 3. Mineralogy (The Composition) The Field Description of Igneous Rocks