Fluorite

Fluorite is a mineral composed of calcium fluoride (CaF2) and aside from having a cool cubic structure also comes in a variety of different colours. The coolest thing about fluorite however is that it fluoresces under ultraviolet radiation. In fact the very word fluoresce comes from this mineral (fluo in latin originally means “to flow” and was given to fluorite because of its uses in iron smelting). However the fluorite itself is not the thing doing the glowing but rather impurities within its crystal structure such as yttrium, europium (which is pictured) or small organic compounds. These and other impurities also give fluorite its diverse range of colours, leading it to be dubbed the “most colourful mineral in the world”. The mechanism of fluorescence is that UV radiation is absorbed by excitation of electrons into higher energy levels. These excited electrons then fall back to the ground state and emit energy in the form of a photon of visible light in the process.

Images: 1, 2, 3, 4

senecacreekphotography:

Banded Iron Formation, Michigan
For all you geologists or nature lovers out there who also love this photo of mine, here is a little background about the photo! This was actually taken on a geology field trip, and not only is it beautiful, but is what sparked my interest in biogeochemistry and symbolizes the first oxygen in the world, without BIFs, we wouldn’t be here breathing!
The Banded Iron Formations (BIFs) are about 2 billion years old and are made of alternating layers of Magenetie (Fe3O4) or Hematite (Fe2O3) which are the grey shiney layers, and red layers of iron stained chert (SiO2) often called jasperite. This photo is part of the Negaunee Iron Formation. Fe2+ is soluble in water, but when iron is oxidized to Fe3+, it is insoluble in water and will precipiate and become a solid. So, the alternating layers represent Iron being oxidized, and precipitation out to form a red layer, and then iron not being oxidized so that you dont get precipitation and get a hematite layer. It is this cycle of there being oxic (oxygen present) and anoxic (no oxygen) conditions in the ocean that has scientists wondering how that could happen.  There are many models that have been put together of how this could happen, but the most interesting one says that ancient bacteria used to use iron as a nutrient. The first bacteria that photosynthesized on our planet produced oxygen, which could explain how the iron was oxidized, precipitated and formed the red layers. Some have said the layers represent the death and birth of algal blooms. Eventually, bacteria produced so much oxygen that all the iron was oxidized, and thus we don’t get BIFs forming in our oceans today since it is impossible to dissolve any iron in it. They even found bacteria in some of the BIFs in Minnesota!  -90% of the world’s BIF (>1014 tons of ore) is located in Australia (~ 27 tons), South Africa, Brazil, and the Lake Superior Region in the US and Canada. The iron that is mined in the UP is extracted from BIFs by grinding them to a powder, taking the iron out through magnets, adding bentonite clay, and then rolling it up into pellets more commonly known as taconite pellets.

senecacreekphotography:

Banded Iron Formation, Michigan

For all you geologists or nature lovers out there who also love this photo of mine, here is a little background about the photo! This was actually taken on a geology field trip, and not only is it beautiful, but is what sparked my interest in biogeochemistry and symbolizes the first oxygen in the world, without BIFs, we wouldn’t be here breathing!

The Banded Iron Formations (BIFs) are about 2 billion years old and are made of alternating layers of Magenetie (Fe3O4) or Hematite (Fe2O3) which are the grey shiney layers, and red layers of iron stained chert (SiO2) often called jasperite. This photo is part of the Negaunee Iron Formation. Fe2+ is soluble in water, but when iron is oxidized to Fe3+, it is insoluble in water and will precipiate and become a solid. So, the alternating layers represent Iron being oxidized, and precipitation out to form a red layer, and then iron not being oxidized so that you dont get precipitation and get a hematite layer. It is this cycle of there being oxic (oxygen present) and anoxic (no oxygen) conditions in the ocean that has scientists wondering how that could happen. There are many models that have been put together of how this could happen, but the most interesting one says that ancient bacteria used to use iron as a nutrient. The first bacteria that photosynthesized on our planet produced oxygen, which could explain how the iron was oxidized, precipitated and formed the red layers. Some have said the layers represent the death and birth of algal blooms. Eventually, bacteria produced so much oxygen that all the iron was oxidized, and thus we don’t get BIFs forming in our oceans today since it is impossible to dissolve any iron in it. They even found bacteria in some of the BIFs in Minnesota! -90% of the world’s BIF (>1014 tons of ore) is located in Australia (~ 27 tons), South Africa, Brazil, and the Lake Superior Region in the US and Canada. The iron that is mined in the UP is extracted from BIFs by grinding them to a powder, taking the iron out through magnets, adding bentonite clay, and then rolling it up into pellets more commonly known as taconite pellets.

Bifringence

Don’t be put off by the name, this phenomenon is also, less dauntingly, known as double refraction. The explanation behind it is also rather simple. In certain crystals, notably calcite, there is a symmetry in the crystal structure with no corresponding symmetry perpendicular to it, a property known as unilateral anisotropy. This axis of symmetry becomes the optical axis. Light that has a polarization (the plane along which the light oscillates) parallel to the optical axis is refracted by some angle, let’s say x, while light that has a polarization perpendicular will be refracted by a different angle y. This means that the light beam entering splits in two to give two separate images. This is also the reason you may see colours on the surface of injection molded plastics as certain wavelengths and polarizations are refracted more than others, producting different colours in different places.

The Platonic Solids

A Platonic solid is a convex geometric shape made entirely of congruent, regular 2D sides. This may seem like it leaves a lot of room for experimentation, but no matter what you try there are only 5: the tetrahedron, hexahedron (cube), octohedron, dodecahedron and the icosahedron (shown in order). The name comes from the famous Greek philosopher Plato, who described the classical elements in terms of these polyhedra with cubes representing earth, tetrahedra as fire, air by octahedra and the icosahedron represented water. The dodecahedron was said to be the material that made the Heavens, an idea that would go on to become that of the aether.

The German astronomer Johannes Kepler also held a fascination with them, believing that the 5 known planets some how corresponded to the 5 platonic solids. As such he became obsessed with forming a model of the solar system where the orbits of the planets were defined according to the geometries of these shapes. Kepler was however forced to abandon this idea but these concepts gave rise to the discovery of elliptical orbits.

The other cool thing about Platonic solids is that each has a dual pair that is another Platonic solid. This means that the vertices of one shape correspond to the faces of another, for example the cube and the octahedron. Some Platonic solids (the cube, octahedron and tetrahedron) also form the basis of crystal structures along with being the body shape of several species of radiolarian (smaller protozoa that form their own mineral skeletons).

When Science and Art CollideI don’t always post about art, but when I do it’s pretty damn awesome. This kite is called “Three Cubes Colliding” and was conceived and designed by Ivan Morison and Sash Reading. The kite itself is made predominantly from aerospace fabric and more than 1700 connectors made using a 3D printer. Its design was inspired by the structure of pyrite along with Alexander Graham Bell’s (the inventor of the telephone) experiments and has a certain “bucky quality” to it.

When Science and Art Collide

I don’t always post about art, but when I do it’s pretty damn awesome. This kite is called “Three Cubes Colliding” and was conceived and designed by Ivan Morison and Sash Reading. The kite itself is made predominantly from aerospace fabric and more than 1700 connectors made using a 3D printer. Its design was inspired by the structure of pyrite along with Alexander Graham Bell’s (the inventor of the telephone) experiments and has a certain “bucky quality” to it.

The Hexagon

Hexagons have to be one of my favorite shapes, it’s hard to say why but I just think they’re neat. They have internal angles that add up to 720 or 4 lots of pi for those who prefer radians (everyone). The other neat thing is that the length between a vertex and the one opposite is twice the length of one of the sides in a regular hexagon. This in turn means that hexagons can be constructed from equilateral triangles. The area for a hexagon is given by the formula A=((3√3)/2)t^2 where t is the length of one of the sides, or alternatively simply A=1.5dt where d is the length between parallel sides. The elegant construction discovered by Euclid is also pictured.

Hexagons also pop up a lot in nature, being the shape of honey combs (for it’s space optimizing ability), igneous basalt columns, crystal structures, benzene rings, snow flakes and the clouds on Saturn’s north pole.

Best Evidence for Water on Ancient MarsFirstly, every time I see a picture or hear something about Mars I’m just like “Woah, dude, we have billion dollar remote controlled cars on Mars… woah…” Secondly this picture shows the most compelling evidence for Mars once having liquid water. It may not look like much, being only the width of a human thumb, but this is a mineral vein, specifically a vein of gypsum, a mineral commonly deposited on Earth through precipitation from water. The theory goes that water flowed into a crack and deposited the crystals as it did so, this also reinforces the theory that there may be water beneath Mar’s surface.

Best Evidence for Water on Ancient Mars

Firstly, every time I see a picture or hear something about Mars I’m just like “Woah, dude, we have billion dollar remote controlled cars on Mars… woah…” Secondly this picture shows the most compelling evidence for Mars once having liquid water. It may not look like much, being only the width of a human thumb, but this is a mineral vein, specifically a vein of gypsum, a mineral commonly deposited on Earth through precipitation from water. The theory goes that water flowed into a crack and deposited the crystals as it did so, this also reinforces the theory that there may be water beneath Mar’s surface.

This is what a submarine volcano looks like. This particular case is just off the coast of the Canary Islands, a tectonic hot zone containing the 3rd largest surface volcano on Earth. This submarine volcano is located a mere 50-100 metres below the surface and has raised the water temperature by 10 degrees Celsius. Along with also churning out various minerals and salts which give the water it’s greeny/grey colour.

This is what a submarine volcano looks like. This particular case is just off the coast of the Canary Islands, a tectonic hot zone containing the 3rd largest surface volcano on Earth. This submarine volcano is located a mere 50-100 metres below the surface and has raised the water temperature by 10 degrees Celsius. Along with also churning out various minerals and salts which give the water it’s greeny/grey colour.

What Happened to Mars’s Water?Every day more and more evidence for Mars’s watery past comes to light. However there is one incredibly pressing question, where did it all go? While some of the water is spread in Mars’s thin atmosphere and other quantities are locked in it’s ice caps it just doesn’t account for all of it. One theory is that the water is actually underground and now it has some evidence. Through analysis of areas of erosion on Mars scientists at the California Institute of Technology found that the most dominant form of clay on Mars was that made from the erosion of volcanic rocks underground suggesting subterranean reserves of water some time in Mars’s past.

What Happened to Mars’s Water?

Every day more and more evidence for Mars’s watery past comes to light. However there is one incredibly pressing question, where did it all go? While some of the water is spread in Mars’s thin atmosphere and other quantities are locked in it’s ice caps it just doesn’t account for all of it. One theory is that the water is actually underground and now it has some evidence. Through analysis of areas of erosion on Mars scientists at the California Institute of Technology found that the most dominant form of clay on Mars was that made from the erosion of volcanic rocks underground suggesting subterranean reserves of water some time in Mars’s past.

it-sfullofstars:

Here’s my meteorite thin section…a chondrite with cute little perfect baby chondrules.
ALSO.  I finally settled on an advisor, and my thesis will probably be related to the research I’m currently helping with (connectivity of core forming melts), so that’s awesome and convenient.  Gotta graduate by the time I’m 30 heh heh.

it-sfullofstars:

Here’s my meteorite thin section…a chondrite with cute little perfect baby chondrules.

ALSO.  I finally settled on an advisor, and my thesis will probably be related to the research I’m currently helping with (connectivity of core forming melts), so that’s awesome and convenient.  Gotta graduate by the time I’m 30 heh heh.

(Source: chondritic)

How Fluorescence Works

I’ve posted a few examples of fluorescence before but never really explained it. In the simplest terms, fluorescence is when light (typically UV) is absorbed by atoms in a material and then remitted at a different wavelength producing a visible glow and colour. The really cool thing about this is that it is often found in biology as can be seen in the scorpion above and several minerals also fluoresce under ultraviolet radiation. It also has a practical application in imaging various parts of cells.