By Goody Clairenstein
Updated Mar 24, 2022
Quartz—silicon dioxide—is one of the most common minerals on Earth’s surface. It appears in many decorative forms such as amethyst, citrine, rose quartz, and smoky quartz. Determining its quality involves discerning whether the stone is natural or a manufactured imitation.
Hold the stone in your palm and compare its heft to a similarly sized plastic reference. Genuine quartz feels noticeably heavier. Additionally, real quartz remains cool to the touch, resembling glass, while synthetic replicas often feel at room temperature. Note that glass designed to mimic quartz will also be cool but tends to be smoother and more uniform.
Natural quartz displays irregular color bands and subtle striations. Inspect for fractures—complete pieces are more valuable, but a naturally colored specimen still outperforms a smooth, manufactured imitation. A gemstone with a dull exterior but a glossy interior typically indicates it was mined from the earth’s surface and is of higher quality.
Using a magnifying glass, examine the stone for fine streaks and irregularities. Authentic quartz will show white streaks and natural irregularities, whereas synthetic glass appears unusually smooth with even color distribution.
Ask the seller for origin details. A “Made In” label often signals a synthetic product. Genuine quartz is usually less expensive because it requires no processing beyond mining. Key natural deposits include:
