Earth: an introduction to physical geology, 10e (tarbuck/lutgens/tasa) 4. 1 multiple-choice questions: lava flows are typically finer grained than intrusive igneous rocks. Diff: 1: which magma is most likely to quench (congeal) to a natural glass, highly viscous; cools quickly, highly viscous; cools slowly, highly fluid; cools slowly, highly fluid; cools quickly. Diff: 1: the sizes, shapes, and arrangements of mineral grains in an igneous rock is known as. ________: silica content, texture, mineral content, bowen"s reaction series. Match the description with the appropriate texture: aphanitic b. porphyritic c. phaneritic d. glassy, ________ magma cools and consolidates without growth of mineral grains. Diff: 1: ________ mineral grains are of roughly equal size and coarse enough to be seen without a microscope or magnifying glass. 1: ________ rock has two or more distinctly different-sized populations of mineral grains. Diff: 1: ________ a magnifying glass or microscope is needed to see individual mineral grains.