What does fine grained extrusive rocks include?

Fine-grained extrusive rocks primarily include volcanic rocks that solidify quickly from lava at or near the Earth's surface, resulting in small crystals. Common examples are basalt, rhyolite, and andesite. These rocks typically exhibit a smooth texture due to their rapid cooling, which prevents the formation of large mineral grains. Additionally, they may contain volcanic glass, such as obsidian, which forms when lava cools extremely quickly.