Clear Quartz (Rock Crystal)

Our selection of rock crystal specimens, otherwise known as Clear Quartz. These pieces are clear or slightly opaque, depending on their quality grade.

Quartz is one of the most abundant minerals in the earth’s crust, and very popular with collectors too.

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Appearance, Uses and History

Clear Quartz is, simply, Quartz that is clear!

It is a transparent to translucent variety of Quartz, commonly colourless, but it may have a tone or some colour due to staining or inclusions. The best specimens are completely colourless, free of impurities, and completely flawless.

Clear Quartz is sometimes used as a gemstone, usually faceted or cut into beads, rather than cut en cabochon. The reason for this is simple – being a clear stone you would be able to see the setting etc through the stone!

Through time, Quartz has been used for the making of jewellery and hardstone carvings – quality pieces of which can be seen during the Roman and Saxon periods.

Optical grade Quartz crystals are used for some very specific purposes, too – telescopes, electronic sensors, microscopes, and lasers. The majority of these, however, are synthetic Quartz crystals grown in a laboratory.

My personal favourite pieces of clear Quartz have some inclusions; needles of Rutile, Tourmaline, Actinolite, Dumortierite… they make extremely attractive specimens.

 

Locales

Clear Quartz can occur all around the world. Quartz is one of the most common minerals on Earth!

Some of the best specimens I’ve seen come from Brazil, China, France, Germany, India, Italy, Slovenia, Spain, Ukraine, and the USA. However, ‘best specimens’ might be biased coming from me – we may like different things.

Mineralogy

Chemistry
Silicon Dioxide, SiO2.
Colours and Variations

Commonly refered to as ‘rock crystal’. I prefer not to use this term, as ‘rock crystal’ can also refer to a type of Lead glass.

Specifically, clear Quartz refers to Quartz that is as clear and colourless as possible.
Staining or inclusions can make it cloudy, yellow, orange, brown or other colours but this section will primarily be clear colourless specimens.

Streak
White
Luster
Vitreous
Fracture
Conchoidal
Transparency
Transparent, translucent – in clear Quartz the more transparent the better.
Crystal habit
Druzy, grainy, geodes, radiating, crystalline, massive, globular, crusty, nodules, etc. Crystal form often occurs as 6 sided prism with a 6 sided pyramid at the end – sometimes dual terminated (pyramids at both ends).
Mohs hardness
7.0
Specific Gravity
2.6 – 2.7
Easiest testing method
Visual inspection, common nature of material, hardness, common conchoidal fractures.
Common Treatments

Hazards and Warnings

Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis.

When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.

Translations

Arabic:

  • الكوارتز واضحة
  • حجر كريستال

Hindi:

  • स्पष्ट क्वार्ट्ज
  • रॉक क्रिस्टल
  • स्फाटिक

Portuguese:

  • quartzo claro
  • pedra de cristal

Bengali:

  • পরিষ্কার কোয়ার্টজ
  • রক স্ফটিক
  • স্ফটিকাবিশেষ
  • একপ্রকার স্বচ্ছ বর্ণহীন স্ফটিক

Indonesian:

  • kuarsa yang jelas
  • batu kristal

Punjabi:

  • ਸਾਫ ਕੁਆਰਟਜ਼
  • ਰਾਕ ਕ੍ਰਿਸਟਲ

English:

  • clear quartz
  • rock crystal

Italian:

  • quarzo chiaro
  • cristallo di rocca

Russian:

  • прозрачный кварц
  • горный хрусталь

French:

  • quartz clair
  • cristal de roche

Japanese:

  • クリアクォーツ
  • ロッククリスタル

Spanish:

  • cuarzo claro
  • cristal de roca

German:

  • klarer Quarz
  • Bergkristall

Korean:

  • 클리어 쿼츠
  • 무색의 수정
  • 락 크리스탈

Thai:

  • หินคริสตัล

Gujurati:

  • સ્પષ્ટ ક્વાર્ટઝ
  • રોક ક્રિસ્ટલ

Mandarin and Traditional Chinese:

  • 透明石英
  • 水晶

Urdu:

  • واضح کوارٹج
  • راک کرسٹل

Further Reading / External Links