31. Some minerals that are commonly associated with akhtenskite are : todorokite, pyrolusite, nsutite, goethite , and cryptomelane. 32. This caused the iron to precipitate out as hematite and goethite to form the innumerable concretions found in the Navajo Sandstone. 33. Thus detrital ferric hydroxides, including goethite and ferrihydrite, will spontaneously transform into red-colored hematite pigment with time. 34. It is thought that eroded craters or minerals directly connected to the existence of liquid water ( such as Goethite ). 35. The iron became fixed in place in the river channels and gradually replaced the existing humic material via replacement with goethite . 36. Two types of laterite can be identified; both types consist of the minerals kaolinite, quartz, hematite and goethite . 37. The main iron oxide is goethite ( FeOOH ), with enough hematite ( Fe2O3 ) to make the soil red. 38. These ferric hydroxides commonly include goethite ( FeO-OH ) and so-called " amorphous ferric hydroxide " or limonite. 39. It is a variety of quartz with fibers of goethite or hematite usually in colors of red, gold, and black. 40. The feces have been preserved due to the replacement of the original fecal material by goethite , siderite and other iron minerals.
