Starting with today we are the happy owners of a new photo camera: Canon 5D MK II. This was our dream since a while ago due to mainly two reasons: full format sensor and its amazing 21 MP resolution. I do not intend to write a full review here, my intention was only to share with you our happiness. I expect more sand photos to come in the near future so stay tuned and visit the Sand Atlas more often ;)
Last year in September we spent an extended weekend on the Usedom island at the Baltic Sea in NE Germany. We couldn’t go bathing but we had plenty of fun exploring the island and discovering its hidden misteries: the Butterfly Farm, the old Russian submarine at Peenemünde (a former Army Research Center during the World War II), the up-side-down house (the entire house is build and fully equipped with the up-side-down), trekking along the former German – Polish border (a sand stripe heavily mined before the Schengen agreement came into power eliminating the border formalities) and of course the delicious smoked fish along the beach.
Talking about beach… I definitely couldn’t just pass by without loading up a full bunch of 30 ml units, samples sorted out and added later to my Sand Atlas: light and fine, a classical “must have” bunch of beach sands (about 20 samples, most of them also available for trading).
Serpentine is a rock forming mineral found in many metamorphic and igneous rocks with chemical formula (Mg,Fe)3Si2O5(OH)4 and chemical name Magnesium Iron Silicate Hydroxide. The colour is mostly green and the crystals are translucent. In my Sand Atlas collection I have one sand with serpentine (no. 278) originating from Marine d’Albo on Corsica island in France (Ligurian Sea).
The sample (832) comes from the beach at Ustka, a Polish holiday resort at Baltic Sea. Probable composition: quartz, garnet and ilmenite, as Polish shorelines of Baltic Sea are known for deposits of sand enriched with heavy minerals such as zircon, garnet, magnetite, ilmenite, rutile, monazite.
Magnetite is a ferrimagnetic mineral known under the chemical name ferrous-feric oxide, having chemical formula Fe3O4. Magnetite is the most magnetic naturally occurring mineral on Earth being known since the ancient times. Magnetite is often found in beach sands with igneous and metamorphic origins.
The sample above comes from Bali island, Indonesia (sample no. 1005 in my Sand Atlas). When taking the photo I noticed some yellow-brown-kaki translucent grains (they were not visible with naked eye). I was just curious to know whether I can somehow sort out the “foreign” grains (presumably olivine).
Using a magnet the result was great: indeed, only some of the particles (about 2/3 from total volume) have been attracted by the magnet, the rest remaining still. I also noticed that not all dark particles were gone, some were ignoring the magnetic force, so that not everything was magnetite.
Sand grains occurr in different shapes and sizes according to mineral composition, age, transport mechanism and distance traveled. Old sands usually have a round shape due to repeated wheatering and action of external factors. If they are exposed to strong wind or tidal action, the roundness of the grains are more accentuated as for the more “static” sands. On opposite, younger sands produced artificially by crushing sandstone tend to be more irregular in shape, with “sharp” edges. Along a river, bigger (and heavier) particles are deposided upstream and the lighter grains are being carried away a longer distance and thus more prone to accentuated roundness.
Two geometrical parameters are used to describe the shape of sand grains, namely roundness and sfericity. Roundness is the measure describing the sharpness of a grain’s corners and edges, regardless of shape. A rather exact description of particle roundness has been proposed in 1932 by a scientist called Wadell as “the ratio of the average radius of curvature of the several edges or corners of the particle to the radius of curvature of the maximum inscribed sphere”. A perfect rounded particle would have the roundness = 1, all the others being included in different roundness classes (see also image below): well rounded (roundness value between 0.60 – 1.00), rounded (0.40 – 0.60), subrounded (0.25 – 0.40), subangular (0.15 – 0.25), angular (0.00 – 0.15), and very angular (class reserved for grains with extremely sharp edges).
Modified after Powers, M . C., 1953, Journal of Sedimentary Petrology, v. 23, p. 118
Sphericity is a measure of the degree to which the shape of a particle approaches that of a sphere. A perfect spherical grain would have the sfericity factor = 1 but this is rather uncommon in nature as most sand grains have sphericity numbers around 0.7 (in the image above, grains on the top line would have high sphericity values and those at the bottom low values).
Although elaborated methods have been developed for exact measuring the both parameters (e.g. by surface area measurement using laser scanner or using shape analysis sofware like ArcInfo), in practice more easier visual methods are used, such as Krumbein roundness chart and Riley sphericity index. For a better exemplification I inserted two images depicting quartz sands with different grain roundness and sphericity(left: subangular grains, right: rounded grains):
More info on roundness and sphericity:
- Krumbein, W. C. and L. L. Sloss (1951) Stratigraphy and Sedimentation. 2nd. Ed. W. H. Freeman and Company. London
- Vepraskas, M. J. and Cassel, D. K. (1987) Sphericity and Roundness of Sand in Coastal Soils and Relationships with Soil Physical Properties. Soil Sci. Soc. Am. J. 51:1108-1112
Over the last weekend we had our first try in sand photomicrography. Since we don’t have (yet!) a microscope we had to use our our digital camera. To get as much sharpness as possible we decided to mount a fix micro lens (Canon EF 100 mm f/2.8 USM) on the Canon 350D SLR body. Additional sharpness was provided by a small aperture (around F22) and a bit longer exposure times, as well as by using the camera’s self-timer and a tripod in order to avoid any hand shaking:
280 NL-NH, Netherlands, Wijk aan Zee, Floodline of beach, GPS 52°29’36″N 4°35’5″E (sea shells beach)
The results were astonishing taking into consideration the simple setup without any professional ligthining (we used only two regular 5 euro desk lights at an horizontal angle of about 15-30° for an increased 3D effect). We are looking so forward to the next photo session…!!!
I got to know Frank Winger more than two years ago when I was just discovering on the world wide web that I am not the only sand freak on this planet. Frank has just welcomed me on the arenophile community and I had with him the second trade in my whole sand collector history. Since then we keep close contact and I have always been amazed by his extraordinary dedication to this hobby. Extremely kind with beginners and always willing to help, Frank is just one of the most enthusiastic sand collectors I have ever met.
A small representation of Frank’s collection
But Frank’s passion is not just kept for himself, instead he created an online presence which attracts since 2002 thousands of visitors fascinated about his extraordinary patience in drawing country maps, marking exact locations of sand samples and nicely organizing everything in logical and easy to navigate menus. Among other characteristic parts of his hobby, Frank is using an unique system of labelling his sand containers in a “more sumptuous way” as he describes it by himself:
Labels for sand containers with detailed information about location of each sample
Besides other fascinating parts of his website I have always been fascinated by the country maps neatly showing the borders of first administrative units. Frank invested a tremenduous amount of work in accurately marking each sample on the map and emphasizing with different colour the administratives units which he’s already got at least one sample from:
Country maps with administrative units and samples’ location (the little red dots)
Just check Frank’s website and enjoy his large sand collection!
This year on September 19th the German sand museum just opened its gates to the public. This was possible due to the tremendous efforts of Ralf Hermann, the initiator and president of German Society for Sand Collecting (Sandsammlerverein e.V.). The housewarming party in Cramme this year was not just a coincidence: “behind the stage” was invested since 1994-1995, when Ralf did the first steps towards sharing his experience and passion with other sand collectors by building the first website dedicated exclusively to the sand collecting hobby. By years his collection grew in a steady-state rythm and today is reaching over 25.000 samples from all over the planet.
Ralf Hermann and his collection of over 25.000 sand samples (Photo: NDR)
The museum was opened in Ralf’s house and the preparations were intense until the last seconds before day zero: the walls had to be painted, the exhibits nicely ordered by themes, everything had to be perfect. Ralf printed even advertising banners and hung them all over the city – a good organised event requires professional PR and Ralf got it just right.
Advertising banners for the sand museum (Photo: Sandsammlerverein e.V.)
But the big day has come and the first visitors entered the museums doors attracted by the original idea. “Sand is not always just… the sand as we know it from beach and rivers” said Ralf Hermann in the opening and he did show it to everybody: industrial applications, art objects (such as the famous sand paintings originally made by native americans), objects from daily life, literature and, of course, the classical hourglasses. A newsletter is also available and it can be obtained by contacting Ralf Hermann at firstname.lastname@example.org.
Should someone consider visiting the museums, this will be possible from Monday to Friday 12:00 am – 5 p.m., excepting Wednesday when the museum is closed. The address is:
An der Meesche 33
Yesterday I decided to change the look of my website and I replaced the old template with a more “high-tech” one. The next step is implementation in WordPress of a powerful but easy to handle photo gallery so that I can keep all the information at hand (so far the Sand Atlas and the Sand Blog were using two different software solutions).
I feel that the new design is a bit more dynamic than the older one and also the colors look more vivid now. The big challenge however is to bring into WordPress the whole image gallery hosting 1,300 (and counting) samples. I already have found one pluggin that might do the job but I am still testing it before the final release.
Later edit (24.06.2010): I decided to not include in the Sand Atlas blog all my 1,300 scans of sands since this would take a huge amount of time and server space. I also realised that my limited free time does not allow me to keep up the scanning rythm and hold my photo gallery up to date.
On the other hand, I have just started recently to photograph sands using a new technique and a new photo camera and the results you can see at Sand Photomicrography section (just click on the photo camera on the top right of the page). This section will be periodically updated but not all sands from my collection will be represented in there.
Feel free to download any sand photo for your personal use (save it to your computer for later view) and note that reproducing the imagery on this website in any way (including further publishing on websites, electronic or printed books, etc) is also allowed BUT ONLY WITH MY AGREEMENT and with clear mentioning the author and the source (“Catalin Stefan | www.sand-atlas.com”). Please write me a short email if you are interested in using any of my imges for private or commercial purpose.