The Earth Story

Potash, evaporating, from space, land and air. Potassium is a vital ingredient of fertilisers, without which the sustainable world population may be something like 2 billion humans, and areas where it can be obtained in a form easily used by plants such a salt are at a premium. Much of the USA gets its stock from mines like the Intrepid mine in Moab, Utah (depicted in the photos) which produces 60% of its supply.

PSYCHEDELIC SALT CAVES

These photos are from the salt mines below Yekaterinburg, Russia. Mine tunnels stretch four and five km some 220m underground, and the fantastic color variation is due to the variability of salt mineralogy: halite NaCl, our common table salt, is generally white; sylvite KCl, used in bitter tasting salt substitutes for folk with high blood pressure, is more often orangey pink in part due to iron inclusions; carnellite KMgCl3.6(H2O) can range between blue and red and tan colors and is the predominate mineral in these mines. Salts are a relatively soft bunch of minerals, and when tectonic forces are applied they can flow and fold easily, creating the psychedelic patterns on these walls. Well, okay, you can also see some circular incisions on the tunnel walls added by drilling exploitation of these deposits. These Russian deposits date to the Permian, yes, ~280 million years ago, when an entire sea dried up (called by some the Perm Sea), leaving behind a salty residue of evaporate minerals in its place. With the vicissitudes of geologic history, these became buried and forgotten until salt was mined in Russia (starting in the 2nd millennia BCE), and only now, with these incredible photos, are we able to view them.

Within these salt mines, the air is ultra-dry, filled with miniscule salt particles, corrosive (endangering electric connections in lights and cameras), and there is constant danger of a cave-in or sudden lead of toxic gasses such as methane, hydrogen sulfide, carbon dioxide. These photographs, now found scattered all over the internet, were taken by a truly intrepid Russian photographer, Mikhail Mishainik.

Annie R

Photos by M. Mishainik, distributed by Caters News Agency.

More reading and pretty pictures at: http://www.huffingtonpost.com/2014/02/06/russian-salt-caves_n_4733182.html?utm_hp_ref=mostpopular http://www.dailymail.co.uk/news/article-2552245/The-psychedelic-salt-Abandoned-Russian-tunnels-mind-bending-patterns-naturally-cover-surface.html http://www.tribunes.com/tribune/sel/logu.htm http://geology.about.com/od/salt/a/aboutsalt.htm http://link.springer.com/article/10.1007/BF02546161#page-1_ _

To lick or not to lick

Sylvite (also called sylvine) is a potassium chloride mineral (KCl). It is similar to halite (NaCl - our well known kitchen salt) and is even isomorphous with it. Sylvite was discovered by the Dutch chemist and physician François Sylvius de le Boe, near the volcanic fumaroles of Mount Vesuvius, in Italy. This mineral is colorless, white or pale yellow, but it can present shades of orange or red due do the presence of hematite inclusions. It is only 2 to 2.5 in the Mohs scale and is very soluble in water, so sylvite specimens should be kept in a closed container to prevent its deterioration by the moisture present in the air. Needless to say that you should never wash this mineral with water.

The first time I held a sylvite speciment in my hand, I had no idea what it was. The color was not of any help to identify it, there was no visible cleveage in that particular specimen and the white streak was as useful as a underwater hair dryer. After checking all of the physical properties I could think of, I was left with two options: to lick or not to lick. “Perhaps this is a salt”, I thought to myself. I just assumed I was not given anything deadly by my teacher (thank you), so licking that thing became my only hope and it worked! That thing was salty and licking it was what allowed me to identify that stuborn mineral. Thinking of it today, that sylvite looked like it was licked many times before I did it. I guess that explains why I could not figure out its habit or cleveage. Anyway, from that day onwards, licking minerals became a trite thing for me to do.

Just so you know, geologists may lick minerals, not only to taste them, but also to check other things. For example, to check if a mineral sticks to the tongue (chrysocolla and kaolinite are minerals that stick to the tongue when licked). Also, by licking a mineral (or rock) you obtain a clearer view, dust free, which improves the appearence of the surface you are trying to observe. Reckless people, do not lick anything, unless you are sure it is not toxic. Many minerals may contain sulphides, mercury, cadmium and lead, so please think before you lick any mineral or rock.

Back to sylvite, this mineral is unknown to the general population, but it is an economically important mineral, since it is a significant source of potassium in fertilizer products. Other uses include aluminium recycling, potassium suplements, metal electroplating and oil drilling fluids. This salty mineral is commonly associated with halite, gypsum, anhydrite and other evaporites. It can be found in many evaporitic deposits worldwide. Best known deposits are in New Mexico and Western Texas, but the biggest one is located in Saskatchewan, in Canada.

Sylvite is not usually part of mineral collections and unless you are studying geology (or working in a sylvite deposit), it is not likely for you to find a specimen, but if you ever do, perhaps you may want to to have a taste of that bitter salt (please be sure it is not something toxic instead!). Some people use a mixture of halite and sylvite in their meals, but if you are not a fan of bitter, this might not be a gourmet option for you.

Su

Sources: http://bit.ly/2y393Gf http://bit.ly/2AmMGgK http://bit.ly/2hejROO Photo credits: http://bit.ly/2j2YXCC - photo by Rob Lavinsky/iRocks.com http://bit.ly/2lSbPwi - photo by André Karwath http://bit.ly/2Aa1gae - photo by Luis Miguel Bugallo Sánchez

Potash, evaporating, from space, land and air.

Potassium is a vital ingredient of fertilisers, without which the sustainable world population may be something like 2 billion humans, and areas where it can be obtained in a form easily used by plants such a salt are at a premium. Much of the USA gets its stock from mines like the Intrepid mine in Moab, Utah (depicted in the photos) which produces 60% of its supply.

The salts are the results of repeatedly evaporated lakes and shallow seas during geological time. The ore here formed some 300 million years ago and is now some 1200 metres beneath more recent rocks. It is mined by pumping water into the layer dissolving the salts into a brine, which then has to be evaporated in the ponds after pumping to the surface in the hot desert sun in order to obtain the desired product. It takes around 300 days, and the electric colours come from a dye that reduces the time taken by darkening the water so that it absorbs more heat.

Loz

Image credits: 1: Digital globe 2: Jassen Todoro/Solent News 3: Doc Searls

Rocks: When to lick, when not to lick

Perhaps this horse has had some geologic training…. because every geologist knows that, in certain cases, licking rocks is surefire way to identify them. My beginning geology students always seem a little…hesitant…to employ their taste buds, but licking rocks is second nature for the seasoned geologist.

The best example of course is halite, the mineral commonly known as salt. To a novice geologist, halite might look a lot like quartz or calcite or gypsum, but none of these will have the distinctly salty taste, so licking it will confirm its identity. (A note to those in introductory geology classes: you’ll never miss halite on exam, if you’re willing to lick it…there can’t be that many germs on in right?)

Are there other rocks or minerals with uniquely distinctive taste? Yes; there is sylvite, a mineral closely related to halite, but with an even more pungent, disgusting salty taste. Then there are the “sticky” minerals, like chrysocolla or kaolinite (a type of clay), which make up in texture what they lack in taste. Their flavor is not distinctive but these minerals will stick to your tongue when you give them a lick—a dead giveaway.

For some rocks, licking won’t work but grinding them against on your teeth will. This is a test for distinguishing between a siltstone and a shale—siltstone will feel gritty against your teeth, shale won’t.

Are there any rocks or minerals that you should leave to your other four senses? Yes, there are, so don’t go crazy trying to get a taste of everything lithological. Certain minerals contain poisonous elements that are not worth accidentally ingesting. For example, there’s realgar (http://on.fb.me/1e9S4b2)—a ruby red ore mineral that contains arsenic; autinite (http://on.fb.me/1JKDqjU)—a dangerous radioactive uranium-bearing mineral; the lead ores, such as galena and cerussite (http://on.fb.me/1KA7bow); and mercury ore minerals like cinnabar (it’s closeness to the word “cinnamon” is no indication of its edibility).

So for any of you just starting your geology careers…perhaps use some sensible caution, but for the most part don’t be afraid to licks the rock in your lab set. Most minerals won’t hurt you…and a little germ swap with your peers is good for the immune system. One of your greatest geologic tools is your tongue!

-CM

Photo credit: Valentina Storti http://bit.ly/1ISh4jY