Properties of Minerals Quiz

Magnetism

• Certain minerals exhibit attraction to magnets, useful for identification.
• To test magnetism, bring a magnet close to the mineral; if they attract, the mineral is magnetic.
• Magnetite is the only prevalent mineral that is consistently and strongly magnetic.

Striations

• Striations are very thin, parallel grooves found on mineral surfaces.
• Visible primarily on one of two sets of cleavages and enhanced by using a hand lens.
• They may be obscured on some cleavage areas; thorough inspection under varying light is recommended to identify them.

Specific Gravity

• Defined as the mineral's weight relative to an equal volume of water, with water having a specific gravity of 1.0.
• Most silicate minerals have specific gravities ranging between 2.6 and 3.4, while ore minerals typically range from 5 to 8.
• High specific gravity can be a distinguishing feature in some minerals, such as barite and galena.

Taste, Odor, Feel

• Some minerals possess a recognizable taste; for instance, halite tastes like salt.
• Certain minerals emit characteristic odors; for example, powdered sphalerite smells like rotten eggs.
• Textural properties are also distinctive; talc is known for its slippery feel.

Chemical Properties

• Chemical properties reveal the atomic arrangement in minerals and inform reactivity.
• Minerals can be distinguished by their reactions to substances; for instance, carbonate minerals often react with acids.
• When dilute hydrochloric acid is applied to calcite, it produces bubbles, indicating the release of carbon dioxide.
• Some minerals, like cinnabar, are toxic, while others, such as halite, are water-soluble.
• Metallic sulfides can degrade into sulfuric acid when exposed to moisture and air.
• Radioactive minerals include Autunite and Thorianite, which contain uranium and thorium respectively.
• Certain metals, like magnesium, are flammable.

Classification of Minerals

• Minerals are categorized by the Dana System into eight basic classes based on chemical composition.
• The classes are: native elements, silicates, oxides, sulfides, sulfates, halides, carbonates, phosphates, and mineraloids.
• This classification aids in understanding the diversity and characteristics of minerals based on their chemical makeup.