This seemed like a great place to start since agate is really easy to acquire. It already comes in a huge variety of colors, but readily takes dye, so it is often sold in eye-catching magenta or teal. You’ll often see large bins of assorted tumbled stones in stores advertising amethyst, sodalite, tiger’s eye and more. If you can’t identify the stone from the chart, it’s usually agate or jasper thrown in as filler because of the bright colors. What kid doesn’t want to dig their hands into a bin of smooth, colorful rocks?