Antlerite Cu3(SO4)(OH)4 The gemstone that balances the Heart meridian is Antlerite. Antlerite is a copper sulfate hydroxide. Antlerite is rare, expensive and often fragile. I looked up the chemistry and found that there is another copper sulfate hydroxide, Brochantite. Chemistry geeks will recognize the two valence states of Copper, Cu+2 and Cu+3 that yield these two.