Aragonite. Erzberg in Styria, Austria. 1875.
The “flowers of iron” from Erzberg in Styria are known the world over for their beauty and quality. Even there, specimens of this size are found only very seldom.
Erzberg in Styria is one of Austria’s largest mines, and the iron ore mineral siderite has been mined there for over a hundred years (wall painting by Robert Russ, Hall II). The flowers of iron found in the siderite cavities at Erzberg were popular collectors’ pieces even in the Early Modern Age. An illustration of the decorative, ramified calcium carbonate mineral aragonite, which is usually snow-white, was published as long ago as 1642 in Michael Besler’s “Cabinet of Remarkable Minerals”. One of the earliest detailed descriptions of these “flowers of iron” dates from the year 1727: “… formed like deer antlers or in the form of beautiful white, shining coral heads, some pieces weighing as much as 7.5 to 11 kg.” Porters carried the large fragile pieces from Eisenerz to Vienna on foot in panniers.
About two million tons of iron ore are still mined at Erzberg every year. This deposit is rather poor and uneconomical compared to Brazil’s beds of iron ore, and at the current rate of extraction will probably be exhausted by the year 2020.
The period during which these flowers of iron were found ended much earlier. As long ago as 1916, papers published by the Geological Society observed that the number and size of aragonite veins – and hence the occurrence of flowers of iron at Erzberg – were declining steadily. Today this brittle mineral is destroyed by the use of explosives and heavy mining machinery.
Although there are many occurrences of flowers of iron around the world, the beauty and quality of the specimens from Erzberg are still considered unique.