GUIDE
Crystal Explorer Guide
Learn together · approximately ages 4–8
Use this grown-up guide to help a child look closely at minerals and crystals, learn careful observation and understand why crystal shapes are clues.
Six facts to share
Minerals build rocks
Minerals are naturally formed materials with a characteristic chemical composition and an orderly internal structure. They are the building blocks of many rocks.
A crystal has an orderly pattern
Inside a crystal, atoms are arranged in a repeating structure. This internal order can produce flat faces and recognisable shapes.
Crystals grow in several ways
Mineral crystals may grow as molten rock cools or as dissolved material comes out of water and becomes solid.
Cooling speed leaves clues
Molten rock that cools slowly underground can grow larger visible crystals; rapid cooling at the surface usually produces much smaller crystals.
Colour is only one clue
Geologists also observe shape, hardness, streak and how light reflects from a mineral.
Quartz comes in many forms
Quartz is abundant in Earth’s crust and occurs in many colours and crystal forms. Pure quartz is colourless and is made from silicon and oxygen.
Explorer word bank
- Mineral
- A naturally formed material with an orderly internal structure and characteristic composition.
- Crystal
- A solid whose atoms are arranged in a repeating pattern.
- Lustre
- The way light reflects from a mineral’s surface.
- Hardness
- How resistant a mineral is to scratching.
- Quartz
- A common mineral made from silicon and oxygen.
Become a crystal detective
Use a safe, clean mineral specimen or pebble, a torch, a magnifying glass, paper and a pencil.
- Look closely without breaking the specimen. Draw its outline and any flat faces.
- Write or say three colour words and three texture words.
- Turn it under a torch. Does it look glassy, sparkly, dull or metallic?
- Compare it with another safe specimen. Record one similarity and one difference.
Ask your explorer
- Which details can you see with a magnifying glass that you missed before?
- Does the specimen have flat faces, curved surfaces or both?
- Why might slowly cooled rock have larger crystals?
- Can you find Crystal Caverns on Dr. Rexington’s map?
Grown-up safety note
Use clean, child-safe specimens with no sharp edges. Do not taste, lick, crush or make dust from rocks or minerals. Wash hands after handling unknown specimens and let a grown-up supervise.