Quartz crystals are silicon dioxide, SiO2. Pure quartz crystals are colorless, but impurities in the structure lead to beautiful colored gems, including amethyst, rose quartz, and citrine. Most natural quartz crystallizes from magma or precipitates from hot hydrothermal veins. Although man-made quartz is produced, the process requires heat not generally possible in a home setting. It’s not a crystal most people want to try to grow at home, since glorious perfect crystals require specialized equipment.
Synthesized quartz is made using the hydrothermal process in an autoclave. You probably don’t have one of those in your kitchen, but you may have a smaller equivalent — a pressure cooker.
If you are truly determined to grow quartz crystals at home, you can grow small crystals by heating silicic acid in a pressure cooker. Silicic acid can be made by reacting quartz with water or by acidification of sodium silicate in aqueous solution. With either technique, the main problem is the silicic acid has a tendency to turn into silica gel. However, the home pressure cooker method of synthesizing quartz crystals is possible. It was done by German geologist Karl Emil von Schafhäutl in 1845, making quartz the first crystal grown by hydrothermal synthesis. Modern techniques can be used to grow large single crystals, but you shouldn’t expect fabulous gems from a home canning system.
Fortunately, there are similar-looking crystals you can grow at home.
One rather spectacular option is to make a fulgurite, which is the glassy shape made by a lightning strike or other electrical discharge into sand (this method is only suggested for experienced professionals). If you’re seeking a large colorless crystal to grow, try alum crystals (much simpler method with directions below).
Here’s how to grow your own quartz crystals at home:
Are you looking for an easy, safe, reliable crystal-growing project? These alum crystals may be the easiest crystals you can grow.
Why This Project Rocks
Non-toxic crystal (alum is a spice)
Uses hot tap water, not boiling water
Easy to do – mix and wait
Extremely reliable results – crystals will grow
Only requires a few hours for good crystal growth
Results in crystals large enough to pick up and examine
Grow Easy Alum Crystal
To grow these crystals you will need:
1/2 cup hot tap water
2-1/2 tablespoons alum
Simply stir the alum into the water and wait for crystals to grow. Alum crystals usually are visible within a half an hour and reach a good size within a few hours. It’s that easy! When the crystals are to your liking, use a fingernail to scrape them off the side of your container. You can examine them and keep them.