"Quartz" comes from the German word "Quarz," meaning whitish stone, which was used historically to describe hard crystalline rocks. it is pure silicon dioxide and colourless, though quartz is colourless, many beautiful varieties of quartz owe their colour to trace elements. These trace elements are what make quartz allochromatic.
Quartz is a naturally piezoelectric mineral, meaning it can generate an electric charge when mechanically stressed, and vice versa. This is due to the asymmetric arrangement of atoms in quartz’s crystal lattice (trigonal structure), which allows electrical polarization under stress. This property is why it’s so valuable in technology, not just in jewelry. However, synthetic quartz is often used in electronics due to its purity and precision needs.
Varieties of Quartz (Gem Types)
Quartz is divided into two main types:
(I) Crystalline Quartz (II)Cryptocrystalline Quartz (III) Phenomenon
Crystalline Quartz (Transparent)
Amethyst --> Purple
Citrine --> Yellow to orange
Smoky Quartz --> Brown to gray
Rose Quartz --> Pink (often cloudy)
Rock Crystal --> Colorless, clear quartz
Ametrine --> Bicolor (amethyst + citrine)
Prasiolite --> Green quartz (rare, often heat-treated
Rutilated Quartz --> golden, silver, reddish, or black strands
Cryptocrystalline Quartz (Translucent to Opaque)
Chalcedony --> Translucent, waxy luster
Carnelian --> Orange-red
Agate --> Banded patterns
Onyx --> Black and white bands
Jasper --> Opaque, spotted, or patterned
Heliotrope --> red to brownish-red spots (Bloodstone)
Pyrites --> metallic brassy-yellow (Fool's Gold)
Phenomenon
Aventurine --> Aventurescence
Iris Quartz --> iridescence
Cats Eye --> chatoyancy
Hawk's Eye --> chatoyancy
Tiger's Eye --> chatoyancy
Asteriated Quartz --> Star Quartz
Major Sources:
Brazil --> Large crystals, amethyst, citrine
Madagascar --> Rose quartz, other varieties
Uruguay --> Fine amethyst
India --> Diverse types, especially chalcedony
USA (Arkansas) --> Rock crystal
Russia, Namibia, Zambia, Sri Lanka --> Various deposits
Citrine is a yellow to golden-orange variety of quartz, valued for its warm, vibrant colour, excellent clarity, and affordability.
Key Facts:
Colour --> Yellow, golden, orange, brownish-yellow
Luster --> Vitreous
Transparency --> Transparent
Treatments:
Heat-treated amethyst or smoky quartz
Amethyst is a purple variety of quartz, cherished for its rich violet to lilac hues. Once considered as valuable as sapphire or ruby, it remains one of the most popular colored gemstones today.
Key Facts:
Colour --> Light lavender to deep purple (sometimes with red or blue flashes)
Luster:--> Vitreous
Transparency: --> Transparent
Treatments:
Heat-treated to enhance or change color
Ametrine is a rare, naturally occurring variety of quartz that displays purple (amethyst) and yellow to orange (citrine) hues in a single crystal. This striking colour zoning makes it a favorite for unique, artistic gemstone cuts and jewelry.
Key Facts:
Colour --> Bi-colour purple and yellow/orange
Luster --> Vitreous
Transparency --> Transparent
Treatment:
Sometimes heat-treated to intensify colour contrast
Prasiolite, also known as green amethyst, is a pale green variety of quartz. Its name comes from the Greek words “prason” (leek) and “lithos” (stone), referring to its soft, leek-green colour. Most prasiolite on the market is created by heat-treating amethyst.
Key Facts:
Colour --> Light green to yellow-green
Luster --> Vitreous
Transparency --> Transparent
Treatment:
Almost always heat-treated or irradiated
Rose quartz is a soft pink to rosy-coloured variety of quartz. Often cut as cabochons, beads, or carved into hearts and figurines, they also show a cat’s eye or asterism (star effect) in rare specimens.
Key Facts:
Colour --> Light pink to rose-pink; may be milky or translucent
Luster --> Vitreous
Transparency --> Translucent to opaque (rarely transparent)
Black onyx is a variety of chalcedony (a cryptocrystalline form of quartz), known for its smooth, jet-black colour and elegant luster. Often used in men's jewelry, cameos, and statement pieces, it exudes a timeless, sophisticated appeal.
Key Facts:
Colour: Solid black (often dyed to enhance)
Luster: Vitreous to silky
Transparency: Opaque
Treatments:
Frequently dyed to deepen the black colour
Bloodstone, also known as heliotrope, is a dark green variety of chalcedony (cryptocrystalline quartz) with distinctive red or brownish-red spots caused by iron oxide inclusions.
Key Facts:
Colour --> Deep green with red, rust, or orange specks
Luster --> Waxy to vitreous
Transparency --> Opaque to semi-translucent
Pyrite is a metallic-looking mineral known for its brassy yellow colour and shiny luster, which often causes it to be mistaken for gold, earning it the nickname “fool’s gold.” Despite this, pyrite has its charm and value in jewelry,
Key Facts:
Colour --> Pale brass-yellow, metallic
Luster --> Mat to Metallic
Treatments:
Stabilization, Coating, Colour Enhancement
(Note: Pyrite is sensitive to moisture and acids, so treated or untreated, it should be stored dry and cleaned carefully.)
Jasper is an opaque, fine-grained variety of chalcedony (quartz), known for its rich colours, patterned surfaces, and incredible variety. It often contains natural swirls, bands, or inclusions of other minerals, giving each piece a unique, earthy appearance.
Key Facts:
Colour --> Red, brown, yellow, green, blue, multicolored
Luster --> Dull to vitreous
Transparency --> Opaque
Treatments:
--> If Jasper appears unnaturally vivid, it is likely dyed.
--> Reconstituted jasper is usually lighter and glossier than solid natural jasper.
--> Sellers may not always disclose treatments, so ask questions or buy from reputable sources.
Carnelian is a translucent to opaque variety of chalcedony (quartz) known for its warm reddish-orange to brownish-red hues.
Key Facts:
Colour --> Orange, red, reddish-brown
Luster --> Vitreous to silky
Transparency --> Translucent to opaque
Treatments:
Heat Treatment, Dyeing, and Sugar-Acid Treatment
Agate is a beautifully patterned, banded variety of chalcedony (quartz), known for its wide range of colours, translucent layers, and swirling or striped patterns.
Key Facts:
Colour --> lored (commonly white, gray, blue, brown, pink, orange)
Luster --> to vitreous
Transparency --> lucent to opaque
Vrieties --> moss agate, blue lace agate, fire agate, and crazy lace agate
Treatments:
--> Dyeing, heat Treatment & Stabilization/Resin Infusion
--> Bright neon or unnatural colors (e.g., hot pink, turquoise blue) almost always indicate dyed agate.
--> Colour concentration along cracks or edges suggests dye penetration.
--> Some dyed agates may fade over time or when exposed to strong sunlight.
Golden Rutilated Quartz is a transparent variety of quartz that contains golden needle-like inclusions of rutile (a titanium dioxide mineral). These brilliant, hair-like inclusions create a striking, shimmering effect often described as "captured sunlight" within the crystal.
Key Facts:
Colour --> Clear to smoky quartz with golden to copper-colored rutile needles
Luster --> Vitreous
Transparency --> Transparent to translucent
Treatments:
--> The rutile inclusions are natural and are rarely altered or enhanced.
--> Untreated golden rutilated quartz is highly prized for its clarity and well-defined rutile patterns.
Black Rutilated Quartz is a captivating variety of clear or smoky quartz that contains black needle-like inclusions of rutile, giving it a dramatic, high-contrast look. Unlike the golden or coppery rutile seen in other types, this version features dark, inky strands that resemble threads of smoke or fine wires suspended in glass.
Key Facts
Colour --> Clear to smoky quartz with black rutile needles
Luster --> Vitreous
Transparency --> Transparent to translucent
Treatment:
--> True black rutilated quartz is prized for its natural contrast of dark needles against clear quartz; enhancements are minimal and typically unnecessary.
Red Rutilated Quartz is a striking variety of clear to smoky quartz that contains reddish to coppery needle-like inclusions of rutile, giving it a warm, fiery appearance.
Key Facts:
Colour --> Transparent to smoky quartz with red–copper rutile needles
Luster --> Vitreous (glass-like)
Transparency --> Transparent to translucent
Treatments:
--> Red rutilated quartz is valued for its natural, dramatic rutile patterns, so treatments are minimal and primarily aimed at enhancing clarity and contrast rather than altering the inclusions themselves.
Silver Rutilated Quartz is a transparent to smoky variety of quartz that contains fine, silvery-white needle-like inclusions of rutile, creating a luminous, ethereal effect as if strands of moonlight are suspended within the stone.
Key Facts:
Colour --> Clear to smoky quartz with silver-white rutile needles
Luster --> Vitreous
Transparency --> Transparent to translucent
Treatments:
Heat Treatment, Irradiation, Clarity Enhancement (Filling) & Coating or Waxing
Star Rutilated Quartz is a rare and mesmerizing variety of quartz that exhibits asterism, a star-like optical effect, due to finely oriented rutile needles intersecting within the crystal. When cut en cabochon with the dome parallel to the rutile “stars,” a sharp, four- or six-rayed star appears to glide across the stone’s surface under a single light source.
Key Facts:
Phenomenon --> Asterism (star effect)
Inclusion Mineral --> Rutile (needles aligned in three or more directions)
Colour of Quartz --> Clear, smoky, or golden host quartz
Luster --> Vitreous
Transparency --> Transparent to translucent
Treatment:
--> Treatments are minimal and always aimed at enhancing clarity and contrast, not altering the star itself.
Scattered Rutilated Quartz is a variety of quartz studded with randomly dispersed rutile needles, creating a dynamic, “snowfall” or “shooting star” effect within the crystal.
Key Facts:
Inclusion Mineral --> Rutile
Appearance --> Clear to smoky quartz with sparse, randomly oriented golden or coppery needle inclusions
Transparency --> Transparent to translucent
Treatments:
Heat Treatment, Irradiation, Clarity Enhancement (Filling) & Coating or Waxing
Cats Eye Quartz is a chatoyant variety of quartz, often a form of tiger’s eye, displaying a sharp, moving band of light (“cat’s eye”) when cut as a cabochon. This effect is caused by parallel, fibrous inclusions (typically crocidolite or quartz fibers) within the crystal.
Tiger’s Eye is a brown to golden-brown variety of quartz known for its chatoyancy (“cat’s eye” or silky banded effect) created by parallel fibrous inclusions of amphibole (originally crocidolite) that have been replaced by silica.
Key Facts:
Colour --> Golden yellow to deep brown with shimmering bands
Luster --> Silky to vitreous
Transparency -->Translucent
Composition --> Quartz pseudomorph after crocidolite
Hawk’s Eye is the blue-grey to blue-green precursor to Tiger’s Eye, formed when fibrous crocidolite (blue asbestos) begins to transform into quartz but retains more of its original blue colour. It exhibits chatoyancy (a silky, moving sheen) similar to tiger’s eye, but with cooler, stormier tones.
Key Facts:
Colour --> Blue-gray to steel blue or bluish-green
Luster --> Silky to vitreous
Transparency --> Translucent
Composition --> Quartz pseudomorph after crocidolite
Iris Quartz, also known as Rainbow Quartz, is a variety of clear quartz that displays a vivid internal rainbow effect when viewed under direct light. This optical phenomenon is caused by internal micro-fractures or thin-film interference within the crystal, which diffracts light into its spectral colours.
Key Facts:
Colour: Clear to translucent with internal rainbow flashes
Luster: Vitreous
Transparency: Transparent to translucent
Star Quartz is a rare variety of quartz that exhibits asterism, a star-like optical phenomenon that appears on the surface of the stone when cut as a cabochon. This effect is caused by oriented, needle-like inclusions (typically rutile or other minerals) aligned in such a way that they reflect light in the shape of a 4- or 6-rayed star.
Key Facts:
Colour --> Usually milky white, gray, or rose quartz with a star effect
Luster --> Vitreous to silky
Transparency --> Translucent to opaque
Aventurine is a variety of quartz known for its distinctive aventurescence, a glittery shimmer caused by tiny mica, fuchsite, or hematite inclusions. The most common colour is green, but it also appears in orange, blue, brown, and grey.
Key Facts:
Colour --> Commonly green; also orange, blue, brown, gray
Luster --> Vitreous to slightly greasy
Transparency --> Translucent to opaque
Inclusions --> Mica (green), Hematite (red), Goethite (gold), others
We use cookies to analyze website traffic and optimize your website experience. By accepting our use of cookies, your data will be aggregated with all other user data.