Greenlandite was discovered in the 1960s during the survey of the large iron deposit, Isukasia north of Nuuk. Greenlandite was subsequently discovered in several localities in the Godhabsfjord area. It was later established that the geological environment in which greenlandite was formed was in the order of 3.8 billion years old. this means that we are talking about one of the earths oldest formations!
Geologically speaking, the rock consist of quartzite with a large content of a green minerals - fuchsite - evenly distributed throughout, giving the stone a fresh green color. Quartzite is made of fine-grained quartz, while the chromium-containing fuchsite resembles glitter, with fine spangles distributed throughout the rock. Greenlandite is a hard mineral, often translucent with a metallic inner glow derived from its many spangles. this type of stone is also known, in the jewelry trade, as aventurine quartz.
Greenlandite has been used as a gemstone in Greenland for many years, justly marketed as “the world’s oldest gemstone”. Green aventurine quartz has long been known as an Indian or Brazilian gemstone, and more recently stones from southern Africa have appeared which can be difficult to distinguish from greenlandite. Experts will note that the color of greenlandite is a more bluish green than that of the foreign variants of aventurine quartz. Any confusion with jade (nephrite) (hardness H=6) can be resolved with a hardness test.
Greenlandites’ two components are quartz (SiO2) with a hardness of H=7 and fuchsite (K(Al,Cr)2AlSi3)10(OH,F)2) with a hardness of H=2.5. As a result the stone is very hard and can readily be polished to a smooth surface. Varying green (fuchsite) and white (quartz) schlieren (streaks) in the same piece can produce many variants of the stone. That indeed is part of greenlandites’ singularity.
For lapidary purposes the most usual form is as a cabochon, but flat polishing also produces pleasing effects. Thin slices are partially translucent, and are therefore well-suited to uses where light can shine through them. Polished greenlandite is best suited to mounting in silver. Superb results have been obtained by mounting in combination with other single-colored gemstones, such as red tugtupite, or blue lapis lazuli.
Greenlandite is well suited to carving for signet rings, for example. the best-known use of greenlandite is in fact in the Bishop of Greenland’s cape. Larger pieces can be used decoratively as bookends or letter racks. It is also well-suited for use in larger stone arrangements, mosaics, and candle holders.