Despite the fact that sugilite has been in production for a relatively short period, there are already reports that it is nearly mined out. No other sizeable deposits of sugilite have been found, so if you haven’t already done so, now’s the time to check it out.
Sugilite, also known as sugulite, sometimes sells under the trade name Royal Azel. The first sugilite to be discovered was a tiny deposit of pink crystals found in Japan in 1944. It was not until 1973, in South Africa, that the massive form of sugilite was found, and that only became commercially available in the late 1970s. The colours of sugilite are typically deep lavender, reddish violet and bluish purple, and a number of different hues are sometimes combined in the form of banding and mottling. Sugilite also comes in yellow-brown, pale pink and black, but these are rarely used for jewelry. The material is translucent to opaque; the gem-quality sugilite has a lovely translucency similar to fine chalcedony but is hard to source. If you’re lucky you might see a drusy form (opaque material with tiny crystals embedded on the surface). Sugilite has a vitreous to resinous/waxy lustre and is often laced with manganese inclusions in the form of black, brown or blue lines.
Sugilite is popular with jewelry makers and buyers because of its beautiful colour. The price is dependent on the intensity of colour and quality of material; vivid translucent stones are expensive. When supplies of sugilite start dwindling, the prices are bound to increase. For now, however, it is still commercially available.
Treatments and imitations
- Sugilite is sometimes given the misnomer purple turquoise. Natural gemstones that closely resemble sugilite include purple or lavender jadeite, charoite, amethystine chalcedony and massive amethyst.
- While no specific sugilite imitation is on the market, some unofficial imitations are available. Barium sulfate in a polymer matrix can be identified because it is softer than sugilite. Dyed magnesite has a more irregular colour distribution. Heat- treated and dyed massive beryl and quartz also imitate sugilite; the dye concentrations can be seen in fractures. Dyed quartzite, known as purple onyx, is also similar in appearance.
- When chalcedony mixes or intergrows with sugilite it becomes purple. A large amount of material labeled as sugilite is actually in part chalcedony-sugilite, which has a greater hardness and a translucency that’s rare in sugilite. This is a natural occurrence, not artificial intervention.
Working with sugilite
- Sugilite has an irregular fracture and its cleavage is poor (in one direction). It is usually cut for cabochons and beads, but its granular structure also makes it suitable for carving and inlay work. It is fairly hard wearing, but needs to be protected from impact.
- Ultrasonic and steam cleaners should not be used. If the piece of jewelry is worn frequently, the gemstone might need repolishing over time.