--- title: Minerals and crystals — a lesson of Mova's school · trees and pragmatics description: «Minerals and crystals», a lesson of the geography course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Rocks are made of minerals, the way a fruit cake is made of flour, sugar and raisins: a mineral is a natural solid with a fixed chemical makeup an --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/) [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/) / Minerals and crystals # Minerals and crystals Lesson 50 of the geography course of Mova's primary school: 15 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/50-minerals-and-crystals/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/0/) — Rocks are made of minerals, the way a fruit cake is made of flour, sugar and raisins: a mineral is a natural solid with a fixed chemical makeup and its atoms arranged in a regular pattern. - [1](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/1/) — When atoms line up in a repeating pattern, the solid grows flat faces and sharp edges: that is a crystal, and the pattern decides its shape, like cubes of salt or six-sided columns of quartz. - [2](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/2/) — Sprinkle salt into warm water, leave the saucer on a sunny windowsill for a week, and tiny cubes appear as the water evaporates; crystals grow by adding atoms layer by layer. - [3](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/3/) — Geologists tell minerals apart like detectives: how hard they are, their colour, their shine, the colour of their powder (streak) and how they break. - [4](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/4/) — That is how they catch fool's gold, pyrite, which glitters like gold but is harder, much lighter and leaves a black streak. - [5](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/5/) — A mineral is a natural solid with a fixed chemical makeup and atoms arranged in a regular pattern. - [6](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/6/) — A crystal is a solid whose atoms are lined up in a repeating pattern, giving flat faces and sharp edges; in glass the atoms are jumbled with no pattern, so glass is not a crystal. - [8](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/8/) — Quartz is one of the most common minerals, made of silicon and oxygen, and most sand is quartz. - [9](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/9/) — Feldspar is the most common mineral group in the Earth's crust. - [10](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/10/) — The Mohs scale ranks minerals from 1 (talc, the softest) to 10 (diamond, the hardest) by which can scratch which. - [11](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/11/) — Geologists identify minerals by hardness, colour, lustre (shine), streak and how they break. - [12](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/12/) — Streak is the colour of a mineral's powder, seen by rubbing it on rough white tile, and it is often more reliable than the colour of the lump. - [14](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/14/) — Rock salt (halite) is a mineral that formed when ancient seas dried up. - [15](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/15/) — Crystals grow when a liquid cools or a solution evaporates, adding atoms layer by layer. - [16](https://md.mova.elamur.ai/free/en/corpora/school/geography/50-minerals-and-crystals/16/) — The Cave of Crystals in Naica, Mexico, holds gypsum crystals up to about 12 metres long, which grew very slowly for hundreds of thousands of years in warm mineral water. - ← previous: [Sedimentary and metamorphic rocks](https://md.mova.elamur.ai/free/en/corpora/school/geography/49-sedimentary-and-metamorphic-rocks/) - next →: [Gemstones and precious metals](https://md.mova.elamur.ai/free/en/corpora/school/geography/51-gemstones-and-precious-metals/) - ↑ back to [Geography](https://md.mova.elamur.ai/free/en/corpora/school/geography/)