Hypabyssal types of these
Hypabyssal types of these rocks form discordant dikes, while plutonic types form cordant laccoliths. Mafic types of these rocks, which contain relatively heavier elements and are exemplified by peridotite, are contrasted with their felsic types including rhyolite. One of these rocks that cools without forming crystals, obsidian, is an extrusive type of these rocks as is basalt, while granite is an extrusive one of these. For 10 points, name this type of rocks formed from magma, contrasted with sedimentary and metamorphic rocks.
Hypabyssal types of these rocks form discordant dikes, while plutonic types form cordant laccoliths.