Quartz crystals are transparent silicates of silicon with oxygen. Their special properties make them invaluable in many applications: hardness and durability make them hardwearing while vibrating them at natural frequencies generates piezoelectric effects which produce an alternating electric field when mechanical stress generates stress induced piezoelectric effects (mechanical stress produces an electric field alternating at natural frequency). Quartz prisms most frequently feature hexagonal prism shapes; however cryptocrystalline and massive forms exist as well.

Physical

Quartz is an extremely hard and durable mineral. Its resistance to acids (except hydrofluoric acid ) makes it resistant to corrosion while having low solubility in water makes it a common vein- and cavity-filling mineral in rocks through which silica-rich waters have moved, while it’s piezoelectric properties allow it to generate electricity when pressure is applied on it.

Quartz crystal is most often encountered as massive feldspar, but can also occur as microcrystalline varieties like agate and onyx or as multiple crystals in one space (druse). While it usually possesses clear hues, impurities may cause different hues. Quartz belongs to the trigonal crystal system with three-fold symmetry and right-handed point group; its oscillation frequency relates directly to mass deposited on electrodes making it an effective electronic sensor material.

Chemical

Pure silica crystal structures are impressively pure, but there will always be some impurity present, which restricts electronic use as the impurities cause distortions in its lattice structure and alter optical properties.

Quartz crystals are usually composed of silica tetrahedra linked together by their corners, creating chains of silica tetrahedra that determine viscosity during magma and lava flows and whether cooling magma will form crystals or not.

Some types of quartz contain minerals other than silica that give it its distinctive colors and aesthetic properties, including smoky quartz (dark brown), rose quartz (pink), amethyst (violet), citrine (yellow to orange) and aventurine (green). Furthermore, inclusions such as air bubbles or filaments of rutile contribute to these rocks’ colors as well.

Optical

Quartz crystals are piezoelectric materials – they produce electric voltage when exposed to mechanical stress – making them useful as tuning forks in radio systems and timepieces, or to produce electronic filters which remove specific electromagnetic frequencies. This characteristic makes quartz crystals popularly used as tuning forks.

Optic grade quartz offers very high transmission from 200-3500nm, making it an excellent material choice for laser applications. Furthermore, its damage threshold and scratch-resistance make it highly resistant to scratches.

QCM can serve as an efficient mass sensitive transducer to screen two orchid viruses (CymMV and ORSV). Kuitio et al. created a QCM immunosensor by directly immobilizing virus-specific antibodies on quartz surfaces, with these sensors capable of detecting viral RNA through reductions in fundamental frequency.

Electrical

Quartz crystals are one of the most transparent materials, from UV to IR wavelengths, demonstrating excellent transparency across a broad spectrum. Their excellent polarization (birefringence) and rotation power make them useful materials for many optical devices.

Trigonal in symmetry and belonging to point group P3221, this crystal system exhibits trigonal symmetry with easy cleavage along rhombohedral faces or less often along prism faces (Fig 5.1).

Quartz is piezoelectric, meaning that when subject to mechanical pressure it generates an electric charge which makes it ideal for measuring fluid pressure such as water or oil in depth gauges, or creating electronic oscillators in timepieces and radio systems. Furthermore, quartz exhibits pyroelectricity when subjected to rapid temperature changes like when heated quickly.

Mechanical

Quartz crystal boasts superior mechanical properties that make it extremely useful in the creation of quartz instruments, quartz crucibles and test tubes, oscillators as well as being used in many digital watches and other electronic devices.

Quartz exhibits various physical properties which depend upon the direction in which a force acts or light travels – this property is known as anisotropy.

Example of A-quartz with Mirror Symmetry Along Four Axes (2 of Them Running Diagonally). This indicates that when viewed from various directions, its appearance will differ slightly, as seen in Figure 5.1.