The Mecklenburg Lake District (in German Mecklenburgische Seenplatte) forms the largest coherent lakes and canals areas in Germany. Part of the federal state of Mecklenburg-West Pomerania (DE-MV), the region is situated in the northern Germany, about half the distance between Berlin and Baltic Sea coast. Because of the abundant lakes and water bodies, the district is also called “the land of thousand lakes” and attracts plenty of tourists during the whole year.

Thanks to my colleague Claudia, who spent there a couple of days during this August, the region is represented in my Atlas of Sands by a couple of nice samples, each collected from a different lake: 816 (Mirower Lake), 817 (Tollensee Lake), 818 (Krakower Lake), 819 (Teterower Lake), 820 (Kummerower Lake), 821 (Malchiner Lake), and 822 (Ivenacker Lake).

Many thanks Claudia!!!

A highlight of our holiday in Romania during the summer of 2008 was a trip to an unique natural reservation: the mud volcanoes from Berca, Buzau county (RO-BZ). The spectacular feature of the reservation consists of 5-6 m high volcano-shaped geological formations caused by eruptions of gas and mud from over 3000 m depth.

Although the “mini-volcanoes” have the same principle as their bigger brothers, the “lava” produced is made of water and clay from underground layers. This is deposited in the form of mud at the top of the volcanoes, with the eruption of gases coming out like some lazy bubbles. The mud is cold and not hot because it is produced inside the Earth’s continental crust layers and not in the mantle. This allowed us to walk free on the Moon-like landscape and take plenty of photographs.

Before leaving, I took a small sample from the dried mud flowing down the slope and noticed that it smells somehow as petroleum. The reason for this might be the petroleum-rich layers traversed by the water and gases in their way to the surface.

Mud volcanoes are something funny and also fascinating, since they allow you to get a glimse on how the “real” ones work, allowing also a very close observation. For those interested and occasionally travelling to Romania, see the sample no 750 in my collection for exact coordinates.

During our trip to Romania this winter I’ve got to learn about a quartz sand quarry not far from the place where we spent most of the time. The sand is industrially exploited by a company called STICLOVAL due to its high purity and suitability for fabrication of glass.

The sands are almost white and have a different content of iron and silica, according to the company’s profile. I was just lucky to receive some samples from different horizons and with different degrees of purity from somebody working in the company – see the numbers 699, 701, 702, and 703:

A relatively rare color of sands in collections is green and this is due to the fact that not so many minerals or combination of minerals can produce it. One of them is called glauconite, an iron silicate from the larger mica group, whose name derives from the Greek glaucos (meaning “gleaming” or “silvery” and referring to its blue-green color, which can vary from bluish green to olive green). The chemical formula of glauconite is K_0.08R¹_1.33R²_0.67[(Al_0.13Si_3.87O₁₀](OH)_2.

The sands containing glauconite can be found in sedimentary deposits along Mediterranean coasts, on sandstone areas near shore, etc. In Europe, the mineral has been used as an oil paint, especially in Russian icon paintings.

In my Atlas of Sands you can find glauconite in samples from two Dutch regions: Groningen (sample no 0636) and Zeeland (sample no 521). The photo above represents the sample no 436, originating from a sand excavation in France (Maisse, Essone region). However, I am not sure about its content in glauconite, despite the beautiful green color displayed.

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Additional info on glauconite:
See the complete mineral fact sheet at Mindat database.

One of my Tunesian sand samples, 0322 TN-KB, comes from Douz, a central town known als “gate to Sahara”. The sample was collected nearby Chott el Djerid, a large salt lake situated at the beginning of the Sahara desert. Because the lake is not connected with any water sources, the water evaporates under the extreme climate and the lake becomes completely dry in summer.

Beside the touristic attraction, the lake was chosen as filming location for some sequences in the Star Wars movie.

The question “how to store my sand samples?” came to my mind since the early beginning and before taking the final decision I had the chance to read about how the others are solving it. I have seen huge collections made of 40 ml glasses uniformly arranged on the walls (e.g. Frank Winger), I’ve seen the sand stored in test tubes of various lengths and diameters (e.g. Gary Buckham) and also square small mount boxes as most collectors in the Netherlands use (e.g. Loes Modderman).

Well, the decision was actually based on more practical than aesthetic reasons: starting to collect sand in another country, I was facing the problem of transporting everything to my country of residence (about 140 samples, plus leftovers for trading), so it had to be small and also available for purchasing in both countries. I have choosen then small 4ml vials from Sigma Aldrich, a chemicals provider very known in Germany. When filled up to the top, the vials can take about 6-7 ml fine sand and they look really nice when displayed together.

But the storage story has not been finished yet. The sand samples were now stored in vials but the next question is: where to store the vials? I didn’t looked very intensively for a solution but for a few months I put the vials in some IKEA drawers. Temporarily OK but not a long time solution since they offered no visibility. Self building was an option too but difficult to realize without proper tools and also due to very small height required: 1.5 cm.

Finally the solution knocked on the door: Gerstaecker, a renowned provider for all kind of stuff related to painting and art, sells drawer boxes for storing pastel paints which perfectly suited my requirements (in four boxes, each having three drawers, I can store 1000 vials).