Kunzite is the pink to violet variety of the mineral spodumene. It forms large, clean crystals in pegmatites, so big faceted stones are common. Kunzite has strong pleochroism, showing deeper color in one direction, and two directions of perfect cleavage that make it tricky to cut and set. Its color can also fade with long exposure to light, so many owners keep it for evening wear.
What kunzite is
Spodumene is a lithium aluminum silicate in the pyroxene group. It is an important ore of lithium, and most spodumene is opaque and gray to white. Gem spodumene is transparent and comes in several colors:
- Kunzite is pink to lilac to violet, colored by manganese.
- Hiddenite is green. Strictly, the name applies to chromium-colored green spodumene, but the trade often uses it for any green spodumene.
- Yellow and colorless spodumene are sold under the mineral name.
Kunzite forms in granite pegmatites, coarse igneous rocks that crystallize from the last, water-rich fluids of a granite magma. Pegmatites are also the source of much gem tourmaline, beryl and topaz. Our page on igneous rocks and gemstones explains how they form. Crystals are long, flat and striated, often with etched surfaces, and some reach the size of a forearm or larger.
George Kunz and the name
Kunzite is named for George Frederick Kunz, a leading American gemologist and longtime gem expert at Tiffany and Co. Pink spodumene from the Pala district of San Diego County, California, was described in the early 1900s and named in his honor. Kunz wrote widely on gems and their folklore, and he championed several American gem materials. Our page on gemstone meanings and folklore covers some of the traditions he recorded.
Sources
California's Pala district produced the original kunzite, and some mines there have yielded fine crystals over the years. Other major sources include:
- Afghanistan, especially Nuristan and the Hindu Kush pegmatites, which produced large, richly colored crystals from the 1970s on. See gems of Afghanistan.
- Brazil, especially Minas Gerais, a long-standing source of pale to medium pink kunzite. See gems of Minas Gerais.
- Pakistan, from pegmatites near the Afghan border.
- Madagascar, which has produced pink and lilac spodumene.
Pleochroism
Kunzite shows strong pleochroism. Looking along the length of the crystal, you usually see the deepest color, often pink to violet. Looking from the sides, the color looks paler or nearly colorless. The page on pleochroism in gemstones explains why some crystals look different in different directions.
Cutters must orient the stone so the deepest color shows through the table. This usually means placing the table perpendicular to the long axis of the crystal. Because crystals are flat and elongated, this orientation wastes more rough, but it gives the best face-up color. A poorly oriented kunzite looks washed out.
Fading
Kunzite's color can fade with long exposure to strong light, especially sunlight. The change can be slow, but over time a pink stone may become paler. Not all kunzite fades at the same rate, and the effect varies with the source and with any treatment.
Some kunzite is irradiated and then heated to deepen or improve the pink color. These treatments are hard to detect. Irradiated color can be especially prone to fading. The page on gemstone treatments explains irradiation and heating.
To keep the color, store kunzite in a dark place, wear it mainly in the evening, and avoid leaving it on a sunny windowsill or dashboard. This is why kunzite has a reputation as an "evening stone."
Cleavage and cutting
Spodumene has two directions of perfect cleavage, at roughly 87 and 93 degrees to each other. A blow or even pressure during cutting can split a stone along those planes. Cutters must work slowly, keep facets angled away from the cleavage planes, and avoid heat buildup during polishing. Our page on cleavage in gemstones explains how cutters deal with this.
Kunzite is about 6.5 to 7 on the Mohs scale, so it resists scratching about as well as quartz. Its weakness is splitting from impact, not scratching.
Wearing and caring for kunzite
Pendants and earrings suit kunzite best. If you choose a ring, use a protective setting and remove it before any physical activity. Large kunzite stones in cocktail rings are popular but need careful wear. Setting a stone with perfect cleavage also needs care, since tightening prongs too hard can split it.
Clean kunzite with lukewarm soapy water and a soft brush. Avoid ultrasonic and steam cleaners, heat and sudden temperature changes, all of which can cause cracks along cleavage planes. For more on safe cleaning, see how to clean jewelry safely.
Buying kunzite
The most desirable kunzite has a strong, saturated pink to violet color seen through the table. Pale stones are common and much less costly. Kunzite is usually very clean, so eye-visible inclusions lower value noticeably. Large clean stones of 10 carats or more are readily available, which makes kunzite popular for statement pieces. Look for good cutting that shows the best color face up.
Kunzite can look similar to pink sapphire, morganite, pink tourmaline and pink topaz. Refractive index, birefringence and pleochroism separate them. Pink morganite is a beryl with weaker pleochroism and lower refractive index.
Frequently asked questions
Does kunzite fade?
Kunzite can fade with long exposure to strong light, especially sunlight. Store it in the dark and wear it mainly in the evening to keep its color.
Who was kunzite named after?
It was named for George Frederick Kunz, an American gemologist who worked with Tiffany and Co. in the late 19th and early 20th centuries.
What is the difference between kunzite and hiddenite?
Both are spodumene. Kunzite is pink to violet, colored by manganese, while hiddenite is green.
Is kunzite good for everyday rings?
It is hard enough to resist scratches, but its perfect cleavage makes it vulnerable to knocks. It is better suited to pendants, earrings and occasional-wear rings.