You will need:
- Scrap piece of cloth
- Stone mortar and pestle
- Clear glass jars
- Canning funnel
- Fine-mesh filter (tea strainers work well)
If the rock is bigger than a Ping-Pong ball, it needs to be broken up. Bring it to a hard surface (like a larger stone) and cover it with a piece of fabric. Use a hammer to hit the stone through the fabric. If it doesn’t break after a few whacks it is too hard for the mortar and pestle.
Gather soft stones. Choose small stones to begin with. Place a rock about the size of a marble in the mortar. Tap the rock lightly with the pestle. Continue tapping, each time a little harder, until the rock breaks open. Now tap on each piece until it breaks into gravel.
Use the pestle in a circular motion with downward and outward pressure to grind the gravel into sand. Keep grinding until the sand turns into powder. The goal with this step is to make pigment that is as fine as flour. When you think you might be getting close, put your fingers in the mortar and feel the texture at the bottom of the bowl. If it feels sandy, keep grinding.
When you are happy with how fine your pigment is, pour it into a jar through a funnel. Hold up the mortar while you use your fingers to sweep the pigments into the funnel. The stone mortars and pestles can be pretty heavy for little kids, so it might be best if older kids do the heavy lifting while younger kids do the “sweeping.” If there are still some larger particles of stone, use a fine-mesh filter to sift them out when you are pouring the pigment into the jar.
The Organic Artist for Kids: A DIY Guide to Making Your Own Eco-Friendly Art Supplies from Nature By Nick Neddo
This craft feature was originally published in JUNO Early Spring 2020