Rose quartz is quartz coloured pale to medium pink, usually translucent to cloudy rather than transparent, and so common that it is sold by the kilogram as tumbled stones, spheres and carvings. It is nevertheless imitated — mainly by pink glass in beads and by dyed quartz or other material in spheres — because even a small margin on a high-volume product adds up.
What rose quartz is
Quartz, with the pink colour attributed to microscopic fibrous inclusions of a mineral related to dumortierite in most massive material, and to titanium-related colour centres in the rare transparent crystalline form. Properties: RI 1.544–1.553, SG 2.65, hardness 7, doubly refractive, usually inert under UV. Massive rose quartz is nearly always cloudy or hazy from the inclusions; transparent, facetable rose quartz is uncommon.
Imitations and substitutes
Pink glass. In beads and bracelets. Singly refractive, bubbles, swirls, uniform transparency — glass is usually clearer than rose quartz, which is itself a clue. Quartz vs glass.
Dyed quartz or quartzite. Crackled clear quartz or white quartzite dyed pink. Dye concentrates in fractures and grain boundaries, visible under magnification; colour is often too vivid or too uniform.
Dyed or pink-coated agate. Chalcedony with pink dye; banded structure visible.
Pink calcite, pink opal, rhodonite, morganite, pink tourmaline. Different minerals, each with its own RI and SG, sometimes confused with rose quartz in the other direction (morganite and pink tourmaline are far more valuable).
Plastic and resin. Light, warm, soft.
How the laboratory identifies it
Polariscope and refractometer on any flat surface; SG on carvings and spheres; magnification for bubbles (glass) versus the fine fibrous haze of natural rose quartz, and for dye in fractures. The characteristic cloudiness with a faint fibrous or silky texture is itself diagnostic to an experienced eye.
Star rose quartz
Some rose quartz contains oriented needle inclusions that produce a six-rayed star when cut as a sphere or cabochon and lit from a point source (the effect is often seen in transmitted rather than reflected light). Star rose quartz is natural and modestly more valuable. It is imitated by glass with an engraved or coated star, which shows on close inspection.
Treatments
Rose quartz is not routinely treated. Dye is applied to poor-quality or crackled material. Some rose quartz fades with prolonged strong light, which is a natural property rather than a treatment.
Frequently asked questions
Why is rose quartz cloudy?
Because of the microscopic inclusions that give it its colour. Clear rose quartz exists but is rare; a perfectly transparent "rose quartz" bead is more likely glass.
Is vivid pink rose quartz natural?
Natural rose quartz is pale to medium pink. Very vivid or hot pink suggests dye or glass.
Does rose quartz fade?
Some material fades slowly in strong sunlight. Store away from direct sun.
Can rose quartz be tested cheaply?
Yes. Identification is quick and the article is usually inexpensive; testing is worthwhile mainly for spheres, carvings and any piece sold at a premium.
Is "strawberry quartz" rose quartz?
No. Strawberry quartz is clear quartz with red hematite or lepidocrocite inclusions. Much "strawberry quartz" on the market is glass with red flecks; the polariscope and magnification decide.