Quartz

Etymology and Early Studies

• The word 'quartz' is derived from the German word 'Quarz' and has origins in Polish and Czech terms.
• Ancient Greeks referred to quartz as 'κρύσταλλος' (krustallos) meaning icy cold.
• Roman naturalist Pliny the Elder believed quartz to be water ice and observed its ability to split light.
• Nicolas Steno's study of quartz in the 17th century paved the way for modern crystallography.

Crystal Habit and Structure

• Quartz belongs to the trigonal and hexagonal crystal systems.
• The ideal crystal shape is a six-sided prism with pyramids at each end.
• Well-formed crystals typically form as a druse, and quartz geodes are fine examples.
• Different types of quartz, such as α-quartz and β-quartz, have chiral crystal structures.

Varieties of Quartz (Microstructure and Color)

• Fibrous quartz, carnelian, aventurine, agate, and onyx are examples of quartz varieties based on microstructure.
• Pure quartz, citrine, rose quartz, amethyst, smoky quartz, and milky quartz are examples based on color.
• Color variations in quartz arise from impurities that change molecular orbitals.
• Chalcedony is a cryptocrystalline form of silica consisting of intergrowths of quartz and moganite.

Specific Quartz Varieties (Blue Quartz, Citrine, Milky Quartz, Rose Quartz, Smoky Quartz)

• Blue quartz contains inclusions of fibrous magnesio-riebeckite or crocidolite and is considered a minor gemstone.
• Citrine ranges in color from pale yellow to brown and is often heat-treated amethyst or smoky quartz.
• Milky quartz is the most common variety and has a white color caused by fluid inclusions.
• Rose quartz exhibits a pale pink to rose red hue due to trace amounts of titanium, iron, or manganese.
• Smoky quartz is a gray, translucent version of quartz that can range from almost transparent to almost opaque.

Uses, Synthesis, and Piezoelectricity

• Quartz has been used in Australian Aboriginal mythology, European passage tombs, and for stone tools.
• The electronics industry relies on quartz crystals.
• Quartz can be synthesized, and high-purity quartz crystals are rare and expensive.
• Quartz crystals have piezoelectric properties and are used in phonograph pickups, oscillators, and clocks.
• Synthetic quartz is primarily used in the electronics industry, while natural quartz is sought after for crystal healing.
• Quartz mining can involve primitive methods and child labor in developing countries.
• Quartz is used in various industrial applications, including glass production, ceramics, and electronics.
• Quartz dust can be harmful to human health and has environmental impacts such as habitat destruction and water pollution.

Quartz Data Sources