Geosciences
Compare and contrast the four basic igneous compositions: basaltic (mafic), granitic (felsic), andesitic (intermediate), and ultramafic. Igneous rocks are composed mainly of silicate minerals. Chemical analyses show that silicon and … Read More
The dark (or ferromagnesian) silicates are minerals containing ions of iron (ferro 5 iron) and/or magnesium in their structure. Because of their iron content, ferromagnesian silicates are dark in color … Read More
It is possible for two minerals with exactly the same chemical composition to have different internal structures and, hence, different external forms. Minerals of this type are called polymorphs (poly … Read More
Mineralogists use the term crystal shape, or habit, to refer to the common or characteristic shape of individual crystals or aggregates of crystals. Some minerals tend to grow equally in … Read More
The source of the weathered mineral matter from which soils develop is called the parent material and is a major factor influencing newly forming soil. Gradually this weathered matter undergoes … Read More
Describe three mechanisms that generate minerals and rocks. Minerals form through a wide variety of processes and in many different environments. We will examine three ways minerals can form: precipitation … Read More
Most minerals you see while walking around an outcrop or a road cut reflect the local geology. The Sierra Nevada in California, which is primarily granitic, has an abundance of … Read More
The word mineral comes from the Latin minera, or mine. Until the nineteenth century, minerals were simply things that came out of mines—things that had economic value, like gold, various … Read More
Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. Topaz crystallizes in the orthorhombic system, and its crystals are mostly prismatic terminated by pyramidal and … Read More
The largest gold nugget ever found In Alaska It weighs a whopping 294.10 troy ounces (9.14 Kilograms, 20.16 pound), and was found near the town of Ruby, Alaska in 1998. … Read More
