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In 1978 Pierre Devismes wrote a book Atlas photographique des mineraux d’alluvions (Photographic atlas of detrital minerals). I believe it remains the best illustrated treatise on detrital minerals to this day. Unfortunately I do not own a copy of it. It is out of print and seems to be impossible to purchase. But [...]
Callan Bentley and Robin Rohrback-Schiavone have gigapanned two more sand samples: pyrite sand and actinolite sand. Thanks!
The first one contains pyrite and silicate grains from Cyprus. The second one is from Ontario, Canada. I have already written about this sample: Actinolite sand from Ontario. I also have to make a small [...] Gigapanning is very useful technology in geology because it allows us to first get a general overview and then zoom in to see smaller structures. It is already used extensively by some members of the geoblogosphere. Thanks to their work we have seen many outcrops in such a detail that was unimaginable before. [...]
Hydrothermally altered granite from Evje, Norway. The green mineral is epidote. The width of the view is 6 cm. I have used the word “hydrothermal” in this blog before and will undoubtedly mention hydrothermal processes many more times in the future. Lots of things can be hydrothermal — hydrothermal vent, hydrothermal alteration, [...] Erik Klemetti wrote about the reasons he loves volcanoes. I love volcanoes also but I am mostly blogging about sand. So I thought that I try to make a list of reasons why sand is interesting and why sand collecting is a great hobby.
1. It matches my interests I am interested in [...] You probably already know that ice is a mineral. But did you know what is its most important use? According to the second edition of Introduction to Mineralogy by William Nesse its most important use is “to cool the drinks that slake the thirst of geologists after long hot days in the field”.
[...] I have a plan to do some geologising in Sri Lanka. Most likely in March. This country has been on my list of places where I want to go for some time.
Unfortunately it is largely quite futile attempt to search for interesting outcrops and geolocations of Sri Lanka in the web. So [...] Sandatlas is now out of baby age. It has together with the article you are reading now exactly 100 articles.
To celebrate that I prepared a patchwork quilt of sand which is composed of 100 photos of interesting sand samples. Unfortunately this is no Gigapan here. You can not zoom in to study [...] While watching the horror movies of mineral destruction at Research at a snail’s pace I noticed that some minerals almost seem to explode. That is of course perfectly normal because these poor crystals got a serious blow from the hammer but there are more issues worth explaining that are deeply connected to the [...]
There seems to be an urban legend that the only beach in the world having green sand is near the southern tip of Big Island (Hawaii). An alternative version is that it is one out of two. The other being in Guam (Talofofo Beach).
I have to first make it clear that this [...] St. George's church in Nördlingen on a postcard from 1919. Image from Wikipedia. Nördlingen is a small town in Bavaria with a population of 19,000. Towns in Southern Germany are very picteresque with their red roofs and timber-framed (fachwerk) houses, but Nördlingen with its history of more than 1,000 years is a [...] I planned to write about sodalite. This is beautiful mineral and I think I have a nice photo of sodalite grains. I sat down and started writing: Sodalite is one of feldspathoid minerals.
And then I thought. What on Earth is this sentence giving to someone who has no idea what is feldspathoid? [...] There are myriad of aspects one has to take into account to get good macro photos. I covered some basic guidelines here: How to take good macro photos. Now I am going through couple of simple to use but extremely helpful tools that helps to make the macro you just took look much [...]
I am testing an extreme macro lens (Canon MP-E 65mm 1-5× Macro) that allows to take shots with 5× magnification. Usually macro lenses have only 1× magnification. What is the meaning of these magnification numbers? It means that with this lens one can take photos of objects that measure only one fifth of [...]
I thought that I do not have anything significant to add to Accretionary Wedge #41. My home country is very quiet geologically. Being far from the plate boundaries we rarely have anything dynamic happening here. I have experienced one earthquake but there is really not much to talk about. But then one event [...]
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CC BY-NC Siim Sepp (sandatlas.org) |
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