41. Desert pavement surfaces are often coated with desert varnish, a dark brown, sometimes shiny coating that contains clay minerals . 42. Traditional ceramic raw materials include clay minerals such as kaolinite, more recent materials include aluminium oxide ( alumina ). 43. As clay minerals promote biomineralization, the presence of bacteria and clay minerals resulted in calcium hydroxyapatite and calcite precipitates. 44. As clay minerals promote biomineralization, the presence of bacteria and clay minerals resulted in calcium hydroxyapatite and calcite precipitates. 45. Gram for gram, the capacity of humus to hold nutrients and water is far greater than that of clay minerals . 46. The OMEGA experiment on Mars Express discovered clay minerals ( phyllosilicates ) in a variety of places in Aureum Chaos. 47. The strongest blocky structure is formed as a result of swelling and shrinking of the clay minerals which produce cracks. 48. Some speculate that there is a " elite or a similar clay mineral in a weak solution " of water. 49. The adjective " argillaceous " is also used to define rocks in which clay minerals are a secondary but significant component. 50. Two canyons were cut in the mound through the layers containing clay minerals and sulfate salts after deposition of the layers.
