Home >> Science & Nature >> Rocks & Minerals

How to Dye Agates

Agates were originally mined from deposits along the Nahe River in Germany. When those deposits were depleted, agates began being imported from similar deposits in Brazil. Though all agates feature iridescent striations or colorful mottling, they come in as many colors and types as quartz. Unfortunately, the colors aren’t usually very bright and the agates must be dyed. You can dye agates yourself at home, though you must use extreme caution and designate an area away from food, pets and children for the process.

Things You'll Need

Undyed agates
Baking soda
Water
Old saucepan
Towels
Large beakers
Balance and weights
Graduated cylinder
Red: iron nitrate
Green: chromic acid or nickel nitrate
Brown: sugar and heat source
Blue: red or yellow prussiate and iron sulphate
Black: sugar and sulphuric acid

Instructions

- 1
  Bring about 3 cups of water to a boil over high heat. Add about 2 cups of baking soda and simmer for 5 to 10 minutes. This creates a bicarbonate solution of about 65 percent strength.
- 2
  Place your agates in the bicarbonate solution and bring it back up to a boil for about 15 minutes. Remove the stones from the solution and place them on a towel. This boiling process opens up the stones to accept other chemical solutions.
- 3
  Measure about 1 gram of your desired chemical (see supplies list for colors) and pour about 100 milliliters of water into your graduated cylinder. Pour them together into a beaker and stir until the chemical is completely dissolved.
- 4
  Place a still-warm agate into your beaker and let it soak for at least 24 hours. You should begin to see a color change after that amount of time. Follow up a sugar soak with a brief immersion in a flame to get brown. Transfer blue agates from prussiate to an iron sulphate solution and black from sugar to sulphuric acid after 24 hours.

Rocks & Minerals