These tumblestones are the best quality you will be able to find.  Perfectly clear.
 
Clear quartz is the most useful and versatile of gemstones for metaphysical work. It has the unique property of being “programmable”, meaning you can infuse it with your intention and then it will amplify it, working on your behalf to manifest it in the world. It also acts to amplify the energies of any other stone you are working with.