I recently received with joy a sand sample from Indonesia. I have actually expected some black sand, eventually magnetite, but for my surprise, nice round foraminifera specimens have shown up from between the other more or less common mineral grains. 2106 ID-BA Indonesia – Bali – Bali island, Beach at Pemuteran
Deep underneath the Earth surface the rocks are exposed to high temperatures and extremely high pressure given by the mass of rock that lay on top of them. These factors may affect their chemical and physical composition and transform them into rocks with new properties and aspect. These are the metamorphic rocks. In real world, [...]
During my trip on the river Elbe (see also my article from yesterday) I found some pieces of material which immediatelly got my attention: a kind of metamorphic “object” that looked almost like a… meteorite (photo width – 40 mm): There was not only one but 8 such things on about 5 m² area and [...]
Yes, that kind of mineral exists in nature under the name fuchsite and it is just a colored form of the common mica found in some sands (original name: muscovite). The gree mica is actually a variety of muscovite very reach in chromium (usually between 1-5%). While the common mica is grey or silver, the [...]
Almandine is a rock-forming mineral with a deep red color (slightly purple) belonging to the garnet group. Chemically, almandine is a iron-alluminium garnet with the formula Fe3Al2(SiO4)3. The name almandine (also known as carbuncle) comes from Alabanda, a region in Asia where the minerals were firstly found in ancient times. The term carbuncle is derived [...]
Fascinated by the photographs in the previous post I searched for more stones in our small stone rack and the results we can see below. Again I don’t know much about their composition but when I’ll know more I’ll update this post so you shall come back later and check this entry.
Yesterday we’ve been walking on the shores of a small lake not far from our house and brought back home a couple of stones. They were just regular stones but after braking them they revealed a nice texture which I though I’d share with you. Even if I know almost nothing about their composition or [...]
Namibia – Erongo – 80 km E of Swakopmund (Langer Heinrich open pit uranium mine) Sample from an open pit uranium mine. There are two types of minerals inside, both of green color. While the one on the bottom-left may be serpentine, I guess the big grain in the middle is malachite.
Yesterday I have received from a trade partner a series of nice sands from Austria, mostly areas around Salzburg and Tirol. The sands are from mountain and, as it was written on the bags, they contain a mixture of quartz, gneis, mica, feldspat and some other elements. The sand has a nice metalic shining under [...]
