Final answer:
The student is inquiring about the identification of minerals using descriptors such as crystal structure, color, texture, and other physical properties. Using these characteristics, students can distinguish between different types of minerals and classify rocks as igneous, sedimentary, or metamorphic. References such as flowcharts and photographs of minerals can further aid in identification.
Step-by-step explanation:
The student's question pertains to the identification of various minerals based on their physical properties such as color, crystal structure, grain size, and other features. For example, minerals with elongated crystals and stubby, prismatic crystals that have small grooves on one of their cleavages are likely indicating traits of striation. Very, very thin, irregular layers of mica may display a satin sheen and can be fine to medium-grained with visible grains and uneven surfaces. Thick bands of white quartz, feldspar, and mica suggest a medium to coarse-grained, banded texture with large crystalline grains.
A mix of quartz, feldspar, and rock fragments that is massive, dark, smooth, and breaks easily, with a dark, oily smell, implies a specific type of igneous rock. Angular fragments that are fine to coarse, very fine-grained, and compact can be a description of certain sedimentary rocks. Descriptions such as 'Massive, black glass' and 'Frothy, gray glass' with subparallel fibers suggest the presence of volcanic glass, while a mention of 'welded quartz sandstone' that fizzes in hydrochloric acid is characteristic of a sedimentary rock with reactive minerals such as calcite.
By evaluating these descriptions, students can determine the mineral's identity by using a flowchart for dark-colored minerals with non-metallic luster or by referencing images of different minerals such as hematite, magnetite, sphalerite, and galena to compare streak colors.