Quartz is the most varied of all minerals and occurs in a vast number of different forms and colours. These include colourless, blue, red, green, yellow, orange, brown, pink, purple, grey, black and many multicolored varieties. Some of the most common named varieties with unique colours include amethyst, citrine, rose quartz, smokey quartz, rutilated quartz and adventurine. Agate, jasper and chalcedony are all also quartz varieties, and display an extensive variety of colour combinations.
Where are they mined?
As one of the most abundant and widely distributed mineral on earth, quartz can be found all over the world. Some of the largest and most impressive quartz crystals come from the Minas Gerais region of Brazil,
including rutilated quartz which is unique to this area. China, Japan, and Russia are the world’s primary producers of quartz, with Australia, Belgium, Bulgaria, France, Germany, South Africa and the United Kingdom also contributing significant quantities to the industry. Herkimer diamonds are named after their origin in Herkimer county, New York, but are also commonly mined in Pakistan.
Qualities to look for
Due to the extensive range of quartz varieties, it is difficult to narrow down quality factors as each type will display its own unique characteristics. Some forms of quartz, such as citrine and amethyst, are frequently heated to produce the desired intensity and shade of colour. Clarity qualities vary depending on the type of quartz, with most high quality crystal varieties displaying no eye-visible inclusions. An exception to this would be quartz with feature inclusions, such as the rutile inclusions in rutilated quartz, or the desired milky translucency of rose quartz and chalcedony. Other varieties, such as agate, onyx and jasper range from transparent to opaque, and their value depends on their unique colour combination and patterning.
How to wear
With such a wide range of colours and patterns available, quartz is an amazingly versatile gem suited to many different occasions, with a hardness of 7/10. Faceted varieties such as rutilated quartz, amethyst and citrine make great everyday gems for fashion and bridal jewellery when the appropriate care is taken. Other quartz types, such as agate and jasper, which display bold colours and patterns and are often cut into slices or cabochons, are better suited for occasional wear in statement or cocktail jewellery.
What makes them special?
Clear quartz crystals were known to the ancient Greeks as ‘krystallos’, which is the origin of the modern word crystal.
Quartz is piezoelectric and pyroelectric, meaning it can turn pressure and heat into electromagnetic energy, and is used in many modern electronics such as microphones, watches, clocks and radios.
It’s heat resistance and durability makes quartz the perfect material for glass-making, and it is used in camera and watch lenses as well as the mirrors in telescopes.
Crystal balls with a mystic significance are made from clear quartz.
Quartz relics dating back to 75,000BC are the earliest talismans known to humans.
In modern day Iraq (ancient Mesopotamia), rose quartz beads have been discovered dating back to 7000 BC.
Quartz was used in healing potions in the Middle Ages by medical practitioners.
In the 1660’s Sir Isaac Newton used quartz prisms to refract white light into its component colours: red, orange, yellow, green, blue and violet. This study resulted in his famous theory of colour.