JMSS Science Practice Test 2026 – Complete Study Resource

This item tests understanding of metamorphism in the solid state—how existing rocks are altered by heat and pressure without melting. Marble forms when limestone, a sedimentary rock, is subjected to heat and pressure that cause the calcite minerals to recrystallize, producing a dense, interlocking crystal texture. The rock changes shape and composition while remaining solid, so there’s no melting involved. That solid-state transformation is why marble is classified as a metamorphic rock. In contrast, granite and basalt come from magma that cools and solidifies (igneous), and sandstone forms from cemented sand grains (sedimentary), not through metamorphism.