Quartz

Quartz is a silicon dioxide mineral (SiO₂) and one of the most abundant crystalline materials in the Earth's crust. The specimen shown here is a rutilated variety — transparent to semi-transparent brown and gold quartz threaded with fibrous rutile needles (titanium dioxide). The broader quartz family spans colorless rock crystal, purple amethyst, yellow citrine, pink rose quartz, gray to black smoky quartz, and cryptocrystalline types such as agate, carnelian, and chalcedony.

Origin and Key Properties of Quartz

Commercial quartz comes from deposits on nearly every continent. Brazil (Minas Gerais and Bahia) remains the largest source of clear, amethyst, citrine, and rutilated quartz. Madagascar supplies rose quartz and smoky material; Arkansas in the United States produces high-clarity rock crystal; Uruguay yields deep-purple amethyst; and the Swiss and Austrian Alps have historically produced collector-grade smoky and faden quartz. Rutilated quartz, like the piece pictured, is mined mainly in Minas Gerais.

Quartz registers 7 on the Mohs hardness scale, with a trigonal crystal system, vitreous luster, and no cleavage — which is why it holds up well in daily-wear rings. Transparency runs from water-clear to translucent to opaque depending on variety and inclusions. Specific gravity sits around 2.65, and the refractive index is 1.544–1.553.

Treatments are common and should be disclosed. Most commercial citrine is heat-treated amethyst from Brazil. Smoky quartz is frequently produced by irradiating clear quartz. Some pale amethyst is heated to deepen color. Rutilated quartz, rose quartz, and rock crystal are typically sold untreated. Dyed quartz and quartz doublets exist in the low end of the market — reputable sellers will state when material is natural versus enhanced.

Quartz in Sterling Silver Jewelry

Transparent varieties (amethyst, citrine, smoky, rutilated, rose) are most often faceted into rounds, ovals, cushions, and emerald cuts to show internal clarity and dispersion. Translucent and opaque types — chalcedony, agate, carnelian — are cut as cabochons or carved. Raw quartz points and druzy clusters also appear in pendants and statement rings. Sterling silver (.925) suits the full color range because the cool metal tone neither competes with warm golden rutile nor flattens cooler purples and pinks. Our quartz jewelry collection covers rings, pendants, earrings, and bracelets typically priced from $25 to $180 depending on size, cut, and variety.

For everyday wear, a bezel-set cabochon in sterling protects the edges of softer inclusions, while prong-set faceted stones maximize light return. Rutilated quartz pendants are a strong choice when you want visible inclusions as the focal point rather than color saturation.

Care and Cleaning

Clean quartz with warm water, mild dish soap, and a soft brush; rinse and dry with a lint-free cloth. Ultrasonic and steam cleaners are generally safe for untreated clear quartz but should be avoided on dyed, fracture-filled, or heavily included stones. Keep amethyst and rose quartz out of prolonged direct sunlight, which can fade color. Store pieces separately in a soft pouch to prevent harder gems (topaz, sapphire, diamond) from scratching the surface, and remove rings before chlorine exposure or heavy lifting.

Frequently Asked Questions