--- title: Igneous rocks and the rock cycle — a lesson of Mova's school · trees and pragmatics description: «Igneous rocks and the rock cycle», a lesson of the geography course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Igneous rocks are "fire rocks": they form when molten rock cools and hardens, either deep underground or on the surface after an erupti --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Geography](https://md.mova.elamur.ai/free/en/corpora/school/geography/) / Igneous rocks and the rock cycle # Igneous rocks and the rock cycle Lesson 48 of the geography course of Mova's primary school: 17 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/geography/48-igneous-rocks-and-the-rock-cycle/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/0/) — Igneous rocks are "fire rocks": they form when molten rock cools and hardens, either deep underground or on the surface after an eruption. - [1](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/1/) — How fast the rock cools decides how big its crystals are: slow cooling deep down gives big crystals, quick cooling in the air gives tiny ones, and very quick cooling gives glass with none. - [2](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/2/) — Think of a granite kitchen worktop with its speckles of grey, pink and black; each speckle is a crystal that grew slowly for thousands of years kilometres underground. - [3](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/3/) — All rocks belong to three families, igneous, sedimentary and metamorphic, and over millions of years each can be turned into the others in the rock cycle. - [4](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/4/) — The Sun drives the outside of the cycle with weather, rain and rivers that wear rock down, and the Earth's inner heat drives the inside by melting and squeezing rock deep down. - [5](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/5/) — Igneous rocks form when molten rock cools and hardens. - [6](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/6/) — Rock that cools slowly underground has big crystals, while lava that cools fast on the surface has tiny crystals. - [7](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/7/) — Granite is a speckled igneous rock with big crystals of quartz, feldspar and mica, formed deep underground. - [8](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/8/) — Granite is seen at the surface only after the rocks above it have been worn away, as on Dartmoor in England. - [9](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/9/) — Basalt is a dark, fine-grained igneous rock made from runny lava and is the most common rock of the ocean floor. - [10](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/10/) — Obsidian is natural glass that forms when lava cools so fast that no crystals can grow. - [11](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/11/) — Pumice is a volcanic rock so full of gas bubbles that it can float on water. - [12](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/12/) — All rocks belong to three families: igneous, sedimentary and metamorphic. - [13](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/13/) — Rocks are slowly recycled from one type into another in the rock cycle. - [14](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/14/) — In the rock cycle, rocks are worn down into bits that make sedimentary rock, changed by heat and pressure into metamorphic rock, or melted and cooled into igneous rock. - [15](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/15/) — The rock cycle is powered by the Sun's energy at the surface and the Earth's inner heat below. - [16](https://md.mova.elamur.ai/free/en/corpora/school/geography/48-igneous-rocks-and-the-rock-cycle/16/) — One trip around the rock cycle usually takes millions of years. - ← previous: [Famous eruptions and living with volcanoes](https://md.mova.elamur.ai/free/en/corpora/school/geography/47-famous-eruptions-and-living-with-volcanoes/) - next →: [Sedimentary and metamorphic rocks](https://md.mova.elamur.ai/free/en/corpora/school/geography/49-sedimentary-and-metamorphic-rocks/) - ↑ back to [Geography](https://md.mova.elamur.ai/free/en/corpora/school/geography/)