Mineral Composition of Igneous Rocks · Earth and Space Sciences Reference Tables (ESSRT)
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The Mineral Composition of Igneous Rocks chart from the Reference Tables for Earth and Space Sciences (ESSRT) shows which minerals make up the common igneous rocks, and in what proportions. It primarily supports HS-ESS2-3.
What the igneous rocks chart shows
Across the top the chart groups the igneous rocks by composition: felsic (granite, rhyolite), intermediate (diorite, andesite), mafic (gabbro, basalt) and ultramafic (peridotite, komatiite). Below, a graph of percent by volume shows how much quartz, potassium feldspar, plagioclase feldspar, muscovite, biotite, amphibole (hornblende), pyroxene (augite) and olivine each kind of rock contains. Arrows under the graph show the trends from one side to the other: silica (from 40% to more than 70%), potassium and sodium increase toward the felsic rocks, while iron, magnesium, calcium and the temperature at which melting begins (650°C to 1400°C) increase toward the ultramafic rocks.
Regents Exam Questions
Released Regents questions that cannot be answered without this table, listed by exam. Each link opens the question with its answer key; the standard is the one the question assesses. The exams through August 2026 were given with the earlier edition of the ESSRT, which has the same table.