Natural coral grains, harvested from the ocean floor off subtropical Okinawa, contain a variety of naturally balanced essential minerals such as calcium, magnesium, zinc, selenium. Currently about 90% of the American market is taking the low-grade coral. To tell the difference, look at the label. It should have at least about 20% calcium and a minimum 10% magnesium from coral calcium.
QNL Products with Sango Marine Coral: