Quartz crystals possess an exceptional ability to oscillate at very precise intervals – known as piezoelectricity – which makes them invaluable components in timepieces and other electronic devices.

Colorful cryptocrystalline quartz varieties boast an astounding variety of patterns and hues, from jasper’s moss-like banding to carnelian’s rich orange hues – each variety offers something truly captivating for its wearer! Together with its other gemological properties, quartz makes an extraordinary gemstone.

Stability

Crystals are widely used in oscillator circuits to produce stable frequencies. Their physical size and shape determine their final or fundamental frequency of oscillation, also known as characteristic frequency.

Resonant frequency can be affected by environmental factors like temperature changes and vibrations as well as noise from other components in a circuit. To maintain stability, crystals should be mounted using mechanical vibration isolation mountings.

Ageing, which refers to frequency changes over time after manufacture, occurs most rapidly immediately following production and decreases with time post-manufacture. To combat ageing effectively, crystals should be manufactured encapsulated in inert gas during their manufacturing and etching should be performed as precisely as possible so as to exclude contaminants from entering their lattice structure. Furthermore, other methods that ensure long-term stability include keeping crystals always within a circuit with low drive levels.

Precision

Quartz crystals possess the purity necessary for vibration at specific intervals when exposed to mechanical stress, known as piezoelectricity, making them perfect for use in electronic timepieces.

Quartz crystals may be clear or contain trace amounts of chemicals that cause slight color variations that vary by the minute; such as purple (amethyst), white, milky blue or black hues. Quartz also sometimes displays crystalline structures or drusen (negative cavities and negative-lined thumbprint marks).

Quartz gemstones include amethyst, rose quartz, rose topaz, smoky quartz and citrine; other variations of quartz include agate, jasper and aventurine. Color variations are achieved through various treatments like dyeing, coating or quench crackling for quench crackling effects to achieve their unique hues. Quartz is a tough mineral that takes a good polish and can be made into decorative and healing gemstones; additionally it has many industrial applications including sandpaper production lines. Quartz can be found within sedimentary rock formations as well as in sedimentary rock as igneous, metamorphic formations.

Inverse piezoelectricity

Quartz crystals use the inverse piezoelectric effect, or piezoelectric conversion, to turn vibrations in their material into voltage – an effect similar to mechanical transducers that convert vibrational energy into electrical signals at specific resonance frequencies (such as tuning forks).

Pierre and Jacques discovered this property of crystal known as quartz by applying pressure to it and noting the electric charge created. Later they coined this phenomenon the piezoelectric effect.

Pizoelectric materials generate electricity when compressed. This occurs because compression causes a shift of positive and negative charges on their surfaces to occur simultaneously, producing voltage U. The same principle holds for applying an electric field directly onto piezoelectric material – applying an electrical field induces mechanical deformation. This was discovered and verified through experimentation by Curies quickly; additionally it’s much simpler than its direct counterpart so can easily be measured using simple equipment or software simulation packages like FEA simulation software.

Resonance

Mechanical flexing of a quartz crystal causes it to vibrate at a certain frequency, with mass, stiffness and dimension all playing key roles in how precisely-defined that frequency is (known as its quality factor or “Q”).

Crystals exhibit several resonance modes when operating at different frequencies, the dominant of which is known as the fundamental mode. Other resonance modes called overtone modes occur at odd-numbered harmonics of this fundamental mode and tend to be less stable; these overtones can be reduced by increasing Q which inversely corresponds to its frequency of operation.

Environmental influences that can alter the frequency of a quartz crystal include power supply voltage, temperature variations, humidity fluctuations, pressure changes and vibrations. Vibration sensitivity can be mitigated by selecting packaging type which minimizes stress on the crystal; for instance, cold weld or resistance weld packages commonly found in high performance OCXO production can help.