A new find of Pyrite in Austria in 2012
by Robert Kunze
Most things we're talking about are history - gone forever. Many locations where beautiful minerals were found in the past are history, too. But it doesn't always mean that there's nothing to find anymore.
Looking in books, talking to older collectors often gave me a feeling that the best locations for field-collecting are dead. Locations in my area, known for great specimens! A sad feeling, especially if there's nothing to get on the market.
Upper Austria, a part of Austria in general is a county that's not very rich in minerals. Only a few locations are known outside of Austria, e.g. Hallstatt (the world's oldest salt-mine) or Luftenberg known for it's fine Apatite, Beryl and Herderite.
2012 for me was not rich in opportunities for field-collecting. So I decided to take a look at some localities in my area. Especially the old quarry in Gusen was interesting. Over decades in the 19th and 20th century Granite was broken and used for streets and buildings.
fig. 1: overview-map of the location (red)
Some general facts:
The Granite is a very dense rock and consists of Feldspar, Quartz and Mica. In some regions in Upper Austria you can find clefts in the Granite, their size reaches from a few Millimeters to several dm! Clefts are generally a good sign for crystallized minerals. Most clefts in this area are filled with mud, containing nothing special or worth collecting.
But in the Gusen quarry it's a bit different. The clefts in some areas are filled with a sandy and bluish clay. This sediment is the base for crystallized Pyrite and Marcasite. In the 1980's local collectors found a cleft with extraordinary dimensions (up to 0,75 m wide). Many very fine Pyrite-crystals and groups were found. The crystal-size reached 4 cm and groups of 20 cm size were recovered. Only a few came on the market and today they're impossible to get.
Back in 2012
Me and my college Hannes visited the Granite-quarry in Gusen for the first time. We didn't expect anything, the quarry is inactive since decades. After a while we found a small spot with a very special smell - the smell of Sulphur. Sulphur is a typical element showing the corrosion of Pyrite in this area. We decided to come back later with equipment and early in the morning, because we didn't like working in the summer sun.
fig. 2: the quarry in Gusen
fig. 3: the Gusen-quarry again
Two weeks later Reggie (my brother in law) and me visited the quarry on a beautiful Sunday morning. We quickly found the spot again. First of all we had to remove a lot of sand and smaller rocks. It was hard work for approx. 2 hours. But then the first signs of Pyrite came out. Small pieces of clay that were glittering from micro crystallized Pyrite. These pieces gave us new energy. One hour later we had a dozens of matrix pieces with high lustrous crystals up to 0,5 cm. Our backs were acing and the sun heated up the quarry leaving no shadow. We decided to cancel our work and to come back next week.
fig. 4: Reggie's removing sand and stones from the Pyrite-spot
Next week we found everything as we left it. Now we were 3 men working. Everything should go easier and faster. After a few minutes we found the first good specimen. It consists of massive Pyrite with some perfect crystals on top. It must have been a vug because more specimens came out undamaged. Our pulse was going faster! Sometimes we only could see the crystal-forms not the Pyrite itself because some pieces were overgrown by a layer of brown Limonite. It was an amazing feeling! We carefully took out one piece after another.
fig. 5: a short break: behind me, at the right hand side, you can see fresh specimens
fig. 6: the spot we found the Pyrite
Half an hour later it was over. All Pyrites were removed and there was only massive Granite around.
fig. 7: that's it, all specimens were removed
fig. 8: fresh specimen next to our tools, a snack and some beer ;-)
After we left the quarry we shared the specimens. All of us had approx. 20 pieces from 3 cm to 25 cm. At this time we had no idea of all specimen's quality because most of them were quite dirty. Only a few crystals were clean and showed an excellent surface before cleaning.
More work than expected:
Back home I started cleaning with water and a simple electric brush. But the results were not satisfying. So I decided to use oxalic-acid to solve the limonite. This step took two weeks, because oxalic-acid needs a lot of time for reaction, but it worked. After 3-4 rounds (6 – 8 weeks) most of the limonite was removed and in autumn 2012 I was holding the cleaned specimens in my hands. The best specimen shows a single, high lustrous and undamaged crystal (1,5 cm) in the middle.
fig. 9: the best specimen with a single 1,5 cm Pyrite in the middle
fig. 10: close up of the crystal
But other pieces are very attractive as well.
fig. 11: a perfect 4,5 cm wide specimen with 3 ideal Pyrite-groups
fig. 12: a 5,5 cm high specimen with a lustrous Pyrite-group
fig. 13: close up
fig. 14: a 6 cm specimen with lots of Pyrite
fig. 15: close up (the surface was covered by a thick layer of limonite and shows a corroded structure)
fig. 16: beautiful, 5,5 cm wide, specimen
As you see there are sometimes possibilities to find good specimens in "dead " locations. It may be worth taking a look, I wish you good luck if you decide to go there.
P.S. what also can be found...