Also referred to as “Black Malachite” Psilomelane (pronounced si-loh’-mi-lane) shares certain visual characteristics with Malachite, such as swills and bands, but is of a very different chemical make-up to the green copper carbonate gem.
This opaque iron black to steely grey mineral from the Silver Crown mine of Chihuahua, Mexico, has sub-metallic lustre and is a common ore of manganese. This hydrous manganese oxide contains amounts of manganese anywhere between 70% - 80%, with variable amounts of barium and potassium intermixed with cryptocrystalline Quartz.
Psilomelane is an amorphous material. Amorphous refers to its internal and exterior structure not having a definite crystalline shape or properties much like opal and obsidian. Crystalline materials have visual and optical properties which vary with direction and are bounded by planes and faces exhibiting a typical crystal form. Amorphous material may crystallise in a space or cavity and take up that shape or area. Its growth habit is that of a mass rather than a single crystal and in Psilmelane’s case may form botryoidal or stalagmitic forms similar to those seen with Malachite.
These habits are responsible for the patterns, swirls and circular banding seen on polished surfaces. As the manganese oxides are deposited, varying saturations of minerals in each layer cause a change in depth of colour and degree of metallic lustre and in turn create the grey and black banding throughout.
Measuring 5 – 7 on MOH’s scale of hardness Psilomelane is still a difficult stone to cut and polish, wearing down blades at a fast rate. Bunny Bedi, owner and designer and Made in Earth, discusses some of the issues that arise when working with Psilomelane. “Cutting Psilomelane has to be the biggest challenge. Buying it already cut in cabochons means it is at an even higher price than the stone already incurs however the cutting process is messy and dangerous. Our cutters need to use a lot of slippery lubricants in order to save our blades from being destroyed. Given that it is a tough stone it can be cut in thin slices or flat cabochons and polished to a high grade of lustre. Retaining the characteristic banding is another challenge all together.”
Psilomelane is a somewhat new stone on the market. Although it was first mined in Mexico in 1940 the single mine then closed in 1947. It opened and closed again a number of times due to the mine being unsafe and collapsing. Only more recently has it begun to produce commercial quantities and we have seen it back on the market in the USA.
Known for its metaphysical properties of energy redirection, it certainly takes a lot of energy to surface this incredible stone. Bunny adds, “On a trip back to Mexico I was lucky enough to meet the miners and discuss this interesting mineral and how it is mined. Among various techniques a lot of explosives are involved and it’s quite a dangerous process. I’m grateful that they are brave and passionate about their job and we’re able to bring this gorgeous mineral to our vast gemstone jewellery collections in Australia and the United States.”
Although not one of the vividly coloured or transparent faceted gemstones that the market is accustomed to; Psilomelane is certainly a beautifully banded and intriguing stone. Its name may be a tongue twister, but Malachite’s long lost Mexican cousin will certainly get people talking and our Psilomelane pendants also look great on both men and women.