Hierve el Agua mountainside. The water has a temperature of . As the water runs down the rock face, it forms large stalactites similar to those found in caves. The flow of water from the spring varies significantly between the dry and rainy seasons. 95% of the surface rock formations are of calcium carbonate; however, lower layers of both rock and water currents are little known as they are sealed by the above layers. The calcium carbonate gives the formations a white or near white appearance, but other minerals that can be present in the water, such as silver, barium and iron can
Calcium supplement is rare, and difficult to achieve without administering calcium intravenously. For example, the oral median lethal dose (LD) for rats for calcium carbonate and calcium chloride are 6.45 and 1.4 g/kg, respectively. Calcium supplements by mouth diminish the absorption of thyroxine when taken within four to six hours of each other. Thus, people taking both calcium and thyroxine run the risk of inadequate thyroid hormone replacement and thence hypothyroidism if they take them simultaneously or near-simultaneously. The intravenous formulations of calcium include calcium chloride and calcium gluconate. The forms that are taken by mouth include calcium acetate, calcium carbonate, calcium