All the best crystals come in varying degrees of toxicity and toxicity is very subjective. A crystal that has a significant amount of toxicity may be considered pretty low toxicity. A crystal that is a little bit too much for you may be considered high toxicity.
The point is that toxicity is something that we all have to face. No matter our backgrounds we all have to face the toxic elements of our lives. Some of us are blessed with a strong immune system, which means that we have a high tolerance for toxins. Others are not so fortunate, and are more susceptible to them. The only way to identify which ones are low or high toxicity is to have a crystal of your choice.