Experiment 5: Microcrystals Under the Microscope
Crystals Experiments Index
1. Simple Crystals on a String. 2. Growing Large Crystals with Seed Crystals. 3. Magic Salt Crystal Garden. 4. Evaporation from a String - Stalagmites and Stalactites. 5. Microcrystals Under the Microscope. 6. Supercooled Chemical Melt.
From JoAnne Nelson (British Columbia Geological Survey)
In this experiment crystals of colored metal compounds are grown in drops of water on glass slides and observed with a microscope. It only takes about 30 minutes for a drop of water with chemicals dissolved in it to completely dry up and crystallize.
What you need.
- Biological (transmitting) microscope. This is the type of microscope designed to view slides with illumination from below the stage.
- Glass slides.
- Dropper bottles containing a saturated solution of any water-soluble transition metal compound such as Copper Sulfate, Ferrous Sulfate, Calcium Chloride.
What to do.
What can be learned.
The round water droplet is like a cross-section of a natural geode, especially with the crystals that grow in from the sides. Geodes in nature form in holes in the rock.
Each compound or mineral has its own characteristic crystal form. Size doesn't matter: form does. Try sketching the various crystals that grow from different solutions. Other solutions to try are salt and sugar. Salt forms little cubes, while sugar crystals are less symmetrical, with less right angles between faces.