Geology rocks Bingo. Yagam1 is our winner!!!

[Fizzbw]

4/10 for me now. I love learning new things in bite sized chunks!

Niki xxxx

[backafteradozenyrs]

Marble puts me at 3/10. Some of these rocks are really pretty!

[rcperryls]

Marble brings me to 4/10. Still steady as she goes. and learning stuff too. I never had a geology course and this is very interesting.

Carole

[geekishly]

Finally got my first numbers with both of todays!

[Lessa54]

Crawling at 2/10 - hoping the weekend brings some luck

[debupnorth]

Had both today, so I'm up to 3/10. Very interesting (& some very pretty rocks ).

[jocellogirl]

Sorry I'm so late tonight. I've been at work all day and had about 15 minutes when I got home to have a bite to eat, kiss the girls, go and introduce ourselves to the new neighbours and then go out to a rehearsal. But I did get a chance to get the girls to pull a number each, so here they are


5. Australopithecus afarensis

Australopithecus afarensis is an extinct hominid that lived between 3.9 and 2.9 million years ago. A. afarensis was slenderly built, like the younger Australopithecus africanus. It is thought that A. afarensis was more closely related to the genus Homo (which includes the modern human species Homo sapiens), whether as a direct ancestor or a close relative of an unknown ancestor, than any other known primate from the same time. The most famous fossil is the partial skeleton named Lucy (3.2 million years old) found by Donald Johanson and colleagues, who, in celebration of their find, repeatedly played the Beatles song Lucy in the Sky with Diamonds.
Australopithecus afarensis fossils have only been discovered within northern Africa, the most extensive remains assigned to the species being found in Hadar, Afar Region of Ethiopia,
Compared to the modern and extinct great apes, A. afarensis has reduced canines and molars, although they are still relatively larger than in modern humans. A. afarensis also has a relatively small brain size (~380–430 cm3) and a prognathic face (i.e. a face with forward projecting jaws).
The image of a bipedal hominid with a small brain and primitive face was quite a revelation to the paleoanthropological world at the time. This was due to the earlier belief that an increase in brain size was the first major hominin adaptive shift.Before the discoveries of A. afarensis in the 1970s, it was widely thought that an increase in brain size preceded the shift to bipedal locomotion (i.e. walking upright on two legs). This was mainly because the oldest known hominins at the time had relatively large brains.
Considerable debate surrounds the locomotor behaviour of A. afarensis. Some studies suggest that A. afarensis was almost exclusively bipedal, while others propose that the creatures were partly arboreal. The anatomy of the hands, feet and shoulder joints in many ways favour the latter interpretation. The curvature of the finger and toe bones approaches that of modern-day apes, and is suggestive of their ability to efficiently grasp branches and climb. Alternatively, the loss of an abductable great toe and therefore the ability to grasp with the foot (a feature of all other primates) suggests A. afarensis was no longer adapted to climbing.
Computer simulations using dynamic modeling of the skeleton's inertial properties and kinematics suggest A. afarensis was able to walk in the same way modern humans walk, with a normal erect gait or with bent hips and knees, but could not walk in the same way as chimpanzees. The upright gait would have been much more efficient than the bent knee and hip walking, which would have taken twice as much energy.
Reconstruction of the social behaviour of extinct fossil species is difficult, but their social structure is likely to be comparable to that of modern apes, given the average difference in body size between males and females (sexual dimorphism). Although the degree of sexual dimorphism between males and females of A. afarensis is considerably debated, males likely were relatively larger than females. These creatures most likely lived in small family groups containing a single dominant male and a number of breeding females. For a long time, no known stone tools were associated with A. afarensis, and paleoanthropologists commonly thought stone artifacts only dated back to about 2.5 million years ago. However, a 2010 study suggests the hominin species ate meat by carving animal carcasses with stone implements. This finding pushes back the earliest known use of stone tools among hominins to about 3.4 million years ago.


5. Basalt

Basalt is a common extrusive igneous (volcanic) rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Basalt is usually grey to black in colour, but rapidly weathers to brown or rust-red due to oxidation of its iron-rich minerals into rust. It almost always has a fine-grained mineral texture due to the molten rock cooling too quickly for large mineral crystals to grow, although it can sometimes be porphyritic, containing the larger crystals formed prior to the extrusion that brought the lava to the surface, embedded in a finer-grained matrix. Basalt with a vesicular or frothy texture is called scoria, and forms when dissolved gases are forced out of solution and form vesicles as the lava decompresses as it reaches the surface. On Earth, most basalt magmas have formed by decompression melting of the mantle. Basalt commonly erupts on Io, and has also formed on Earth's Moon, Mars, Venus, and even on the asteroid Vesta. The crustal portions of oceanic tectonic plates are composed predominantly of basalt, produced from upwelling mantle below ocean ridges.
Basalt is used in construction (e.g. as building blocks or in the groundwork), making cobblestones (from columnar basalt) and in making statues. Heating and extruding basalt yields stone wool, an excellent thermal insulator.
The shape, structure and texture of a basalt is diagnostic of how and where it erupted—whether into the sea, in an explosive cinder eruption or as creeping pahoehoe lava flows, the classic image of Hawaiian basalt eruptions. Basalt which erupts under open air (that is, subaerially) forms three distinct types of lava or volcanic deposits: scoria; ash or cinder (breccia); and lava flows. Basalt in the tops of subaerial lava flows and cinder cones will often be highly vesiculated, imparting a lightweight "frothy" texture to the rock. Basaltic cinders are often red, coloured by oxidized iron from weathered iron-rich minerals such as pyroxene. `A`a types of blocky, cinder and breccia flows of thick, viscous basaltic lava are common in Hawaii. Pahoehoe is a highly fluid, hot form of basalt which tends to form thin aprons of molten lava which fill up hollows and sometimes forms lava lakes.


Lava flow

Lava tubes are common features of pahoehoe eruptions. During the cooling of a thick lava flow, contractional joints or fractures form. If a flow cools relatively rapidly, significant contraction forces build up. While a flow can shrink in the vertical dimension without fracturing, it can't easily accommodate shrinking in the horizontal direction unless cracks form; the extensive fracture network that develops results in the formation of columns. The topology of the lateral shapes of these columns can broadly be classed as a random cellular network. These structures are predominantly hexagonal in cross-section, but polygons with three to twelve or more sides can be observed.The size of the columns depends loosely on the rate of cooling; very rapid cooling may result in very small (<1 cm diameter) columns, while slow cooling is more likely to produce large columns.

Columnar jointing at Fingal's Cave on the Hebridean island of Staffa.

When basalt erupts underwater or flows into the sea, contact with the water quenches the surface and the lava forms a distinctive pillow shape, through which the hot lava breaks to form another pillow. This "pillow" texture is very common in underwater basaltic flows and is diagnostic of an underwater eruption environment when found in ancient rocks. Pillows typically consist of a fine-grained core with a glassy crust and have radial jointing. The size of individual pillows varies from 10 cm up to several meters.
The island of Surtsey in the Atlantic Ocean is a basalt volcano which breached the ocean surface in 1963.
Basalt is one of the most common rock types in the world. The largest occurrences of basalt are in the ocean floor that is almost completely made up by basalt. Above sea level basalt is common in hotspot islands (e.g. Hawaii) and around volcanic arcs, especially those on thin crust. However, the largest volumes of basalt on land correspond to continental flood basalts. Continental flood basalts are known to exist in the Deccan Traps in India, the Chilcotin Group in British Columbia, Canada, the Paraná Traps in Brazil, the Siberian Traps in Russia, the Karoo flood basalt province in South Africa, the Columbia River Plateau of Washington and Oregon.
Many archipelagoes and island nations have an overwhelming majority of its exposed bedrock made up by basalt due to being above hotspots, for example, Iceland and Hawaii
The dark areas visible on Earth's moon, the lunar maria, are plains of flood basaltic lava flows. These rocks were sampled by the manned American Apollo program, the robotic Russian Luna program, and are represented among the lunar meteorites. Basalt is also a common rock on the surface of Mars, as determined by data sent back from the planet's surface and by Martian meteorites.

[Ketta]

Up to 3/10!

[backafteradozenyrs]

Nope, neither one for me today.

[rcperryls]

I knew it wouldn't last. Still at 4/10. But very interesting today, especially the history of the fossil. I never thought of this as geology, but more archeology. But I see hoe they could be closely connected.

Carole

[yagam1]

Basalt takes me to the half-way point. 5/10

[jocellogirl]

Late again, sorry. Rehearsing until 9.30 and the same tomorrow. However, when I was out, the girls did their duty and chose numbers;

10. Corundum

Corundum is a crystalline form of aluminium oxide (Al2O3) with traces of iron, titanium and chromium. It is a rock-forming mineral and is one of the naturally clear transparent materials, but can have different colours when impurities are present. Transparent specimens are used as gems, called ruby if red and padparadscha if pink-orange. All other colours are called sapphire, e.g., "green sapphire" for a green specimen.


Sapphire


Ruby

Because of corundum's hardness, it can scratch almost every other mineral. It is commonly used as an abrasive, on everything from sandpaper to large machines used in machining metals, plastics, and wood.
Corundum occurs as a mineral in mica schist (remember that one?!), gneiss, and some marbles in metamorphic terrains. Other occurrences are as masses adjacent to ultramafic intrusives, associated with lamprophyre dikes and as large crystals in pegmatites.


Corundum in a pegmatite.

Sapphire from Madagascar

It commonly occurs as a detrital mineral in stream and beach sands because of its hardness and resistance to weathering. The largest documented single crystal of corundum measured about 65 × 40 × 40 centimetres (26 × 16 × 16 in).
Corundum for abrasives is mined in Zimbabwe, Russia, Sri Lanka and India. Historically it was mined from deposits associated with dunites in North Carolina, USA and from a nepheline syenite in Craigmont, Ontario. Emery grade corundum is found on the Greek island of Naxos and near Peekskill, New York, USA. Abrasive corundum is synthetically manufactured from bauxite.
In 1837, Marc Antoine Gaudin made the first synthetic rubies by fusing aluminium at a high temperature with a small amount of chromium as a pigment. In 1847, Ebelmen made white sapphires by fusing aluminium in boric acid. In 1877 Frenic and Freil made crystal corundum from which small stones could be cut. Frimy and Auguste Verneuil manufactured artificial ruby by fusing BaF2 and Al2O3 with a little chromium at temperatures above 2,000 °C (3,632 °F). In 1903, Verneuil announced he could produce synthetic rubies on a commercial scale using this flame fusion process. The Verneuil process allows the production of flawless single-crystal sapphires, rubies and other corundum gems of much larger size than normally found in nature. It is also possible to grow gem-quality synthetic corundum by flux-growth and hydrothermal synthesis. Because of the simplicity of the methods involved in corundum synthesis, large quantities of these crystals have become available on the market causing a significant reduction of price in recent years. Apart from ornamental uses, synthetic corundum is also used to produce mechanical parts (tubes, rods, bearings, and other machined parts), scratch-resistant optics, scratch-resistant watch crystals, instrument windows for satellites and spacecraft (because of its transparency from the UV to IR), and laser components.
Corundum is one of the ten defining minerals of the Mohs scale of mineral hardness, having a hardness of 9.



13. Fluorite

Fluorite (also called fluorspar) is a halide mineral composed of calcium fluoride, CaF2. The word fluorite is derived from the Latin root fluo, meaning "to flow" because the mineral is used as a flux in iron smelting to decrease the viscosity of slags at a given temperature. In 1852 fluorite gave its name to the phenomenon of fluorescence, which is prominent in fluorites from certain locations, due to certain impurities in the crystal. Fluorite also gave the name to its constitutive element fluorine.


Fluorescing fluoride crystals under ultra violet light.

Fluorite is a colourful mineral, both in visible and ultraviolet light, and the stone has ornamental and lapidary uses. Fluorite has been called "the most colourful mineral in the world", the most common colors being purple, blue, green, yellow, or colourless. Less common are pink, red, white, brown, black, and nearly every shade in between. Colour zoning or banding is commonly present. The colour of the fluorite is determined by factors including impurities, exposure to radiation, and the size of the colour centers.


Fluoride crystal

Fluoride carving

Industrially, fluorite is used as a flux for smelting, and in the production of certain glasses and enamels. The purest grades of fluorite are a source of fluoride for hydrofluoric acid manufacture, which is the intermediate source of most fluorine-containing fine chemicals. Optically clear transparent fluorite lenses have low dispersion, so lenses made from it are used in microscopes and telescopes. Fluorite optics are also usable in the far-ultraviolet range where conventional glasses are too absorbent for use. Natural fluorite mineral has ornamental and lapidary uses. Fluorite may be drilled into beads and used in jewellery, although due to its relative softness it is not widely used as a semiprecious stone.
Fluorite may occur as a vein deposit, especially with metallic minerals, where it often forms a part of the gangue (the surrounding "host-rock" in which valuable minerals occur) and may be associated with galena, sphalerite, barite, quartz, and calcite. It is a common mineral in deposits of hydrothermal origin and has been noted as a primary mineral in granites and other igneous rocks and as a common minor constituent of dolostone and limestone.
Fluorite is a widely occurring mineral which is found in large deposits in many areas. Notable deposits occur in China, Germany, Austria, Switzerland, England, Norway, Mexico, and both the Province of Ontario and Newfoundland and Labrador in Canada. Large deposits also occur in Kenya in the Kerio Valley area within the Great Rift Valley. In the United States, deposits are found in Missouri, Oklahoma, Illinois, Kentucky, Colorado, New Mexico, Arizona, Ohio, New Hampshire, New York, Alaska, and Texas. Fluorite has been the state mineral of Illinois since 1965. At that time, Illinois was the largest producer of fluorite in the United States, but the last fluorite mine in Illinois was closed in 1995.
Cubic crystals up to 20 cm across have been found at Dalnegorsk, Russia. The largest documented single crystal of fluorite was a cube 2.12 m in size and weighing ~16 tonnes.
One of the most famous of the older-known localities of fluorite is Castleton in Derbyshire, England, where, under the name of Derbyshire Blue John, purple-blue fluorite was extracted from several mines or caves, including the famous Blue John Cavern. During the 19th century, this attractive fluorite was mined for its ornamental value. The mineral Blue John is now scarce, and only a few hundred kilograms are mined each year for ornamental and lapidary use. Mining still takes place in both the Blue John Cavern and the nearby Treak Cliff Cavern.


Blue John Bowl.

Fluorite is one of the ten defining minerals of the Mohs scale of mineral hardness, having a hardness of 4.

[SunnyDay]

I've gotten 4/10 so far. Sorry, haven't been on much. I have had a wee bit of trouble this week. I will try to check in a little more frequently.

[rcperryls]

I knew 4 days in a row was not going to last. Still at 4/10 and still enjoying this.

Carole

[diamondradleylover]

Ooo, I had both of todays numbers! Your information is fantastic!
I'm at 5 out of 10

[geekishly]

got one yesterday and both today, so up to 5/10!

[yagam1]

None of the numbers for today. Staying at 5/10 for the day.

[Fizzbw]

Got fluorite, and it's one of my fav crystals!

5/10 now for me.

Niki xxx

[debupnorth]

Both rather pretty, but didn't do it for my score, still 3/10.

[jocellogirl]

Here are tonight's numbers. Tomorrow will be earlier, promise!!


9. Coprolite

Sorry about this one folks. If you are of a delicate disposition, you may not want to read the info. I suggested this one to the girls as a joke and children being children, they begged me to include it, so here it is.

A coprolite is fossilized faeces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name is derived from the Greek words kopros, meaning 'dung' and lithos, meaning 'stone'. They were first described by William Buckland in 1829. Prior to this they were known as "fossil fir cones" and "bezoar stones." They serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms. Coprolites may range in size from a few millimetres to over 60 centimetres.
Coprolites, as opposed to paleofaeces, are fossilized animal dung. Like other fossils, coprolites have had much of their original composition replaced by mineral deposits such as silicates and calcium carbonates. Paleofaeces, on the other hand, retain much of their original organic composition and can be reconstituted to determine their original chemical properties.
The fossil hunter Mary Anning had noticed that "bezoar stones" were often found in the abdominal region of ichthyosaur skeletons found in the Lias formation at Lyme Regis. She also noted that if such stones were broken open they often contained fossilized fish bones and scales as well as sometimes bones from smaller ichthyosaurs. It was these observations by Anning that led the geologist William Buckland to propose in 1829 that the stones were fossilized faeces and named them Coprolites. Buckland also suspected that the spiral markings on the fossils indicated that ichthyosaurs had spiral ridges in their intestines similar to those of modern sharks, and that some of these coprolites were black with ink from swallowed belemnites.
By examining coprolites, paleontologists are able to find information about the diet of the animal (if bones or other food remains are present), such as whether it was a herbivorous or carnivorous, and the taphonomy, the study of decaying organisms over time and how they become fossilized (if they do), of the coprolites. In one example these fossils can be analyzed for certain minerals that are known to exist in trace amounts in certain species of plant that can still be detected millions of years later. In another example, the existence of human proteins in coprolites can be used to pinpoint the existence of cannibalistic behavior in an ancient culture. Parasite remains found in human and animal coprolites have also shed new light on questions of human migratory patterns, the diseases which plagued ancient civilizations, and animal domestication practices in the past.
The recognition of coprolites is aided by their structural patterns, such as spiral or annular markings, by their content, such as undigested food fragments, and by associated fossil remains. The smallest coprolites are often difficult to distinguish from inorganic pellets or from eggs. Most coprolites are composed chiefly of calcium phosphate, along with minor quantities of organic matter.
Coprolites have been recorded in deposits ranging in age from the Cambrian period (540 to 485 million years ago) to recent times and are found worldwide..
In 1842 the Rev John Stevens Henslow, a professor of Botany at St John's College, Cambridge discovered coprolites just outside Felixstowe in Suffolk in the villages of Trimley, Falkenham and Kirton and investigated their composition. Realising their potential as a source of available phosphate once they had been treated with sulphuric acid, he patented an extraction process and set about finding new sources. Very soon, coprolites were being mined on an industrial scale for use as fertiliser due to their high phosphate content. The major area of extraction occurred over the east of England, centred around Cambridgeshire and the Isle of Ely with its refining being carried out in Ipswich by the Fison Company. Today, there is a Coprolite Street near Ipswich docks where the Fisons works once stood. The industry declined in the 1880s but was revived briefly during the First World War to provide phosphates for munitions. A renewed interest in coprolite mining in the First World War extended the area of interest into parts of Buckinghamshire as far west as Woburn.


I don't really think this needs a caption, does it

24. Pegmatite

A pegmatite is a very crystalline, intrusive igneous rock composed of interlocking crystals usually larger than 2.5 cm in size, the rock type being based purely on grain size rather than mineralogy.
Crystal size is the most striking feature of pegmatites, with crystals usually over 5 cm in size. Individual crystals over 10 metres across have been found, and the world's largest crystal was found within a pegmatite. Similarly, crystal texture and form within pegmatitic rock may be taken to extreme size and perfection.
Pegmatites can be classified according to the elements or mineral of interest, for instance "lithian pegmatite" to describe a Li-bearing or Li-mineral bearing pegmatite, or "boron pegmatite" for those containing tourmaline.
There is often no meaningful way to distinguish pegmatites according to chemistry due to the difficulty of obtaining a representative sample as the individual crystals are so large, but often groups of pegmatites can be distinguished on contact textures, orientation, accessory minerals and timing. These may be named formally or informally as a class of intrusive rock or within a larger igneous association.
Pegmatite localities are only well recorded when economic mineralisation is found, as Pegmatites contain many exotic and important minerals, including gemstones.

Pegmatite with huge beryl crystals