Mining-Prospecting Dictionary

• Q ualitative analysis: Determining which metals are present in a sample.
• Quantitative analysis: Determining how much of a metal is present.
• Quartz: Silicon dioxide; a common gangue mineral.
• Quartz: 1. Crystalline silica, an important rock-forming mineral. It is, next to feldspar, the commonest mineral, occurring either in transparent hexagonal crystals (colorless, or colored by impurities) or in crystalline or cryptocrystalline masses. Quartz is the commonest gangue mineral of ore deposits, forms the major proportion of most sands, and has a widespread distribution in igneous, metamorphic, and sedimentary rocks. 2. A general term for a variety of no crystalline or cryptocrystalline minerals having the same chemical composition as that of quartz, such as chalcedony, agate, and opal.
• Quartzite: 1. A granoblastic metamorphic rock consisting mainly of quartz and formed by recrystallization of sandstone or chert by either regional or thermal metamorphism. 2. A very hard but unmetamorphosed sandstone, consisting chiefly of quartz grains that have been so completely and solidly cemented with secondary silica that the rock braks across or though the grains rather than around them. The cement grows in optical and crystallographic continuity around each quartz grain, thereby tightly interlocking the grains as the original pore spaces are filled.
• Quaternary: The second period of the Cenozoic era, following the Tertiary; also, the corresponding system of rocks. It began two to three million years ago and extends to the present.
• Quench Tank: A tank filled with water or oil where metals and alloys, or any substance are immersed to rapidly cool the material to below the critical range.