Discovery and Occurrence
Pinolith (also known as pinolite) is an exclusive blend of magnesite, dolomite and graphite, and is commercially important both as a magnesite ore and as a decorative stone. For those who desire to learn more about the unique history and geology of pinolith, encountering the ancient magnesite mining site in the Sunk Valley, in the Austrian section of the Alps known as the Hohe Tauern in the province of Styria, is a pleasant obligation.
In brief geological terms, the magnesite deposit in Sunk Valley is located in the clastic, marine carbonate rocks of the “Veitscher Decke” (a geological nappe in the area of Veitsch) in the eastern greywacke zone. Within the deposit, spar magnesite is spread over three beds, which, in turn, seem to be embedded in the alpidic tectonics. With depth, the superficial beds descend towards northwest at an angle of 30° to 40° and eventually dissolve into cylindrical and lentil-shaped bodies. No wonder, then, that the rare pinolith was found just there, and as its specific geological conditions of formation are unparalleled, it has never been discovered anywhere else in Austria or the world.
Magnesite mining in Sunk
The antiquity of the location is reflected in its very name: “Hohe Tauern” is derived from the Celtic root “thauer,” meaning “mountain pass.” While mining of many minerals has taken place in the Hohe Tauern Mountains for thousands of years, the magnesite quarry known locally as “Bruch im Sunk” has persisted longer than most mines. Graphite, one of the constituent minerals of pinolith, was also extracted separately, closer to the present-day small town of Trieben. Both are located in Sunk Valley, right in the heart of Austria, and constitute one of the mining centerpieces of the Hohe Tauern.
The mining of pinolith in Sunk Valley was first explicitly mentioned in records dated around 1850. However, given its ancient and current use as a high-class building stone, pinolith mining may well have a history far older than that. A document from 1614 describing the high altar’s side pillar in St. Stephen’s Cathedral in Vienna mentions a “black and white mottled Styrian marble,” a clear reference to pinolith. Another record is preserved from 1865, when, after a devastating fire, the ancient monastery of Admont was rebuilt using pinolith, and there are quite a number of additional historical references to this unique variety of magnesite stone.
Large-scale, commercial magnesite ore mining in Sunk Valley, however, did not commence until 1907. During the next 84 years or so of the mine’s existence, approximately 5.5 million tons of magnesite were wrested from the mountains, oftentimes at risk of the pitmen’s lives. However, the mining of magnesite slowed and eventually stopped upon the termination of the mining contract with the landowner in 1991.
Pinolith mining started up again in 2013 with a different company, committed to the careful stewardship of the stone and its host mountain. With its accessibility to tourism and focus on historical roots, pinolith brings Sunk Valley and the Hohe Tauern, a fascinating geological location, into the public eye. The “edelweiss stone” thus simultaneously tells its history and paints an exciting picture of its future. Because one thing is certain: pinolith is poised to become the famous and unique European stone and gemstone that it truly deserves to be.
