Australian Golden Prehnite’s vibrant lustrous golden-greens, and soft radiating inner glow, define its unique natural beauty. With an attractive blend of Australia’s national colors, Australian Golden Prehnite’s beautiful fusion of greens and golds are reminiscent of Australia’s national flower, the Wattle (Mimosa). Much like the Wattle, Prehnite is also synonymous with Australia. Hailing from the world’s finest source, Australian Golden Prehnite is unearthed in scant quantities from desolate tablelands surrounding Wave Hill Station in Australia’s Northern Territory. Usually green, Australian Prehnite with natural golden hues is exceedingly rare and highly prized. Despite the scarcity of its finest qualities, this little-known Antipodean gem, is actually wonderfully wearable.
Hardness 6 – 6.5
Refractive Index 1.611 – 1.669
Relative Density 2.82 – 2.94
Prehnites’ major value determinants are color, translucency, luster, and lapidary quality. Australian Golden Prehnite’s mesmerizing translucency affords an ethereal appearance that is key to its beautiful appeal. This signature translucency in combination with Australian Golden Prehnite’s bright, almost luminescent, swirling hues, excellent clarity for this gem, and fine pearly luster, results in one of the world’s most attractive and distinctive gemstones.
Due to its quality, Australian Golden Prehnite can be both faceted or polished ‘en cabochon’ (cut in convex form and highly polished, but not faceted) in a variety of attractive shapes that beautifully captures its fresh golden hues and translucency. Displaying an excellent luster only when correctly polished, Australian Golden Prehnite is optimally cut by experienced lapidaries, with a superior mirror-like polish affording an excellent luster. When cut as cabochons, Australian Golden Prehnite is carefully polished into attractive smooth domes with an excellent finish, proportion and shape. When faceted, Australian Golden Prehnite also maintains a high-polish/luster, as well as an attractive overall appearance (outline, profile and proportions).
Purportedly the very first gemstone named after an individual, Prehnite is coined for Colonel Hendrik Von Prehn (1733 – 1785), governor and commander of the military forces of the Dutch colony at the Cape of Good Hope (1768 – 1780). A naturalist and mineralogist, Colonel Prehn discovered the mineral in 1774 at the Cradock District of the Cape Colony in South Africa’s Eastern Cape Province, also bringing its first mineral specimens to Europe. In 1788 it was analyzed and named Prehnite by the famous German geologist, Abraham Gottlob Werner (1749 – 1817). Prehnite was also the very first gem named and described from South Africa, long before this country became an important source of gemstones. Colonel Prehn spoke Dutch, English, and German, and was regarded as a well-informed and accomplished man, with an interest in science. When Captain James Cook visited the Cape on his second expedition in 1772, Colonel Prehn introduced two members of the expedition, the zoologists J.R. Forster and his son J.G.A. Forster, to the visiting Swedish naturalist, Anders Sparrman, which resulted in Sparrman joining the expedition. Prehnite is a hydrous, calcium aluminum silicate found in igneous/basaltic and metamorphic rocks, typically forming with a coarse crust and crystalline quality. Usually pastel yellow-green to grass green, Prehnite can also be blue, colorless, golden, gray, pink, and white. Rare orange Prehnite was discovered in South Africa’s Kalahari Manganese Fields in April, 2000. On extremely rare occasions, Prehnite can display the cat’s eye effect. Also known as chatoyancy, this reflection effect caused by inclusions appears as a single bright band of light across the surface of a gemstone. Prehnite has some interesting, albeit incorrect, common names; the Chinese call it ‘Grape Jade’ due to its aciniform (shaped like a cluster of grapes) crystal formations; while others refer to it as ‘Cape Emerald’, due to its historic location and an appearance similar to Green Beryl. Also known as the ‘Prediction Stone’ among spiritual healers, Prehnite is believed by some to enhance dreaming and remembrance.
The original South African deposit still yields Prehnite, as well as Mali and Namibia, but with better-quality, larger crystals, Australia is the world’s premier source.
Notable Prehnite deposits cover thousands of square kilometers in Western Australia’s East Kimberley and at Kalkarindji (pronounced: ‘Kal-car-in-gee’, also Wave Hill) in the Northern Territory’s adjoining Victoria-Daly Region. Gemmy Australian Prehnite is primarily unearthed from extensive deposits in the basalt tableland surrounding Wave Hill Station, that have been fossicked since the 60s. Although Australia possesses about 90 percent of the world’s Prehnite reserves, gem-quality remains very scarce, with its finest golden and top green hues, only representing around two percent of all Australian Prehnite.
Mine-to-market, Australian Golden Prehnite is ethically and sustainably artisanally mined near Wave Hill Station. Remote and inhospitable, this expansive deposit is worked during the cooler winter months (June – August), typically using semi-mechanized mobile camps. While the miners have access to several locations in the area, most crystals are heavily fractured and generally included, making them unsuitable for lapidary. Australian Golden Prehnite’s cut yield is also very low, less than three percent, noting the typical gem mineral return is 20 – 35 percent.
Australian Golden Prehnite are also one of the few gemstones that are totally natural and unenhanced, accentuating their rarity and desirability. Given most Golden Prehnite in the marketplace is irradiated, this is especially significant.
Durability & Care
An excellent jewelry gemstone (Mohs’ Hardness: 6 – 6.5), Australian Golden Prehnite should always be stored carefully to avoid scuffs and scratches. Clean with gentle soap and lukewarm water, scrubbing behind the gem with a very soft toothbrush as necessary. After cleaning, pat dry with a soft towel or chamois cloth.