Jasper
Jasper is an opaque, impure form of microcrystalline quartz (chalcedony), containing up to 20 percent or more of other minerals. These impurities give jasper its wide variety of colours and patterns. Red, coloured by iron oxide, is the most common colour, but jasper also occurs in yellow, brown, green, grey, black and, rarely, blue, often in combinations of spots, stripes, swirls and landscape-like patterns.
There are hundreds of trade names for jasper, many based on appearance or place of origin. Well-known types include red jasper, picture jasper (with scene-like patterns), ocean jasper (with orb-shaped patterns, from Madagascar), poppy jasper, brecciated jasper (broken fragments cemented together), mookaite (from Western Australia), Kambaba jasper (green with dark circles), zebra jasper and leopard skin jasper. Some stones sold as jasper, such as Dalmatian jasper and ocean jasper, are actually different rocks, but the trade names are widely used.
The name comes from the Greek "iaspis", meaning spotted or speckled stone. Jasper has been used since prehistoric times for tools, beads and seals; it was carved into seals on Minoan Crete around 1800 BC and is mentioned as one of the stones in the breastplate of the High Priest in the Bible.
Jasper is durable and takes a good polish, which makes it very popular for beads, cabochons and carvings. Some jasper, and stones sold under jasper names, may be dyed to create brighter colours; dyed jasper is often used to imitate lapis lazuli, turquoise and other stones.
Jasper at a glance
| Colour | Red, yellow, brown, green, grey, black, rarely blue; often patterned |
|---|---|
| Hardness (Mohs scale) | 6.5 – 7 |
| Composition | Silicon dioxide with iron oxides, clays and other minerals |
| Crystal structure | Trigonal; microcrystalline aggregate |
| Lustre | Vitreous to dull |
| Transparency | Opaque |
| Where it is found | India, Madagascar, Australia, Brazil, South Africa, Russia, Indonesia, China, Mexico and USA |
| Birthstone | March (traditional) |
Caring for jasper
Jasper is fairly hard (6.5 – 7 on the Mohs scale) and has no cleavage, making it durable for everyday jewellery. Clean it with warm soapy water and a soft brush, then rinse and dry. Avoid harsh chemicals and prolonged heat, especially with dyed or stabilised jasper. Ultrasonic and steam cleaning are best avoided. Store separately from harder gems to avoid scratches.
In folklore
The beliefs below are traditional folklore, included for interest. They are not scientifically proven, and nothing here is medical advice.
Jasper was one of the most popular stones of the ancient world. It was believed to bring rain, drive away evil spirits and protect against snakebite. Ancient warriors wore jasper amulets for courage, and it was used in the seals and signet rings of many cultures. Jasper is one of the twelve stones of the High Priest's breastplate and the first foundation stone of the New Jerusalem described in the Book of Revelation. It is associated with the zodiac signs Aries, Leo, Virgo and Scorpio.
Jasper is traditionally known as the "supreme nurturer" and is associated with stability, strength and grounding. Crystal healing lore holds that it brings tranquillity and wholeness, supports the wearer through times of stress and encourages courage, determination and quick thinking. Each colour and variety is given its own meaning; red jasper, for example, is linked to energy and the root chakra.
Related stones
Chalcedony, agate, chert, bloodstone (heliotrope), carnelian and tiger iron. Popular jasper varieties include red, picture, ocean, poppy, brecciated, Kambaba, zebra, leopard skin, Dalmatian and mookaite jasper. Dyed jasper is used to imitate lapis lazuli ("Swiss lapis"), turquoise and sugilite.
For the technically minded
| Scientific name | SiO2 (with impurities) |
|---|---|
| Density | 2.50 – 2.90 |
| Refractive index | 1.54 |
| Double refraction | Not detectable |
| Cleavage | None |
| Streak | White, yellow, brown or red |
| Fluorescence | Generally inert |