41. Desert pavement surfaces are often coated with desert varnish, a dark brown, sometimes shiny coating that contains clay minerals . 42. From 1947-1949 there were again unsuccessful attempts to mine the remaining clay minerals in eastern field of the mine. 43. The OMEGA experiment on Mars Express discovered clay minerals ( phyllosilicates ) in a variety places in Aureum Chaos. 44. Shales are typically composed of variable amounts of clay minerals and quartz grains and the typical color is gray. 45. Some speculate that there is a " elite or a similar clay mineral in a weak solution " of water. 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. Gram for gram, the capacity of humus to hold nutrients and water is far greater than that of clay minerals . 49. Two canyons were cut in the mound through the layers containing clay minerals and sulfate salts after deposition of the layers. 50. The adjective " argillaceous " is also used to define rocks in which clay minerals are a secondary but significant component.
