Just for fun I thought I'd post a something that is humorous at the expense of my beloved subject and give y'all a link to the geologist page on unencyclopedia:
http://uncyclopedia.wikia.com/wiki/Geologist
My favourite parts of this include 'how to spot a geologist' and the recount of the failed reality television programme that was basically 'I'm a geologist, get my out of here', only it was the camera crew and the television station that caved before the geologists did.
At this point I should say that a recent documentary called 'How to build a volcano' featured real life geologists with real life yellow note books who wrote actual scientific papers about the results. I might actually do a run down of the work done off the back of the show as I found it really interesting as it is a beautifully elegant model of how volcanoes may actually erupt.
Anyway, Happy Christmas!
Buy an nice pair of socks for a geologist for Christmas... they'll go nicely with their sandals!
Friday 23 December 2011
Tuesday 13 December 2011
Diamonds...
So recently I've been thinking a lot about diamonds, make of that what you will! Diamonds are a polymorph of carbon which basically means depending on the temperature or pressure carbon will take on different molecular structures.
This helpful diagram below will show you what I mean:
This helpful diagram below will show you what I mean:
Diamonds come from deep within the Earth and are transported to the surface via Kimberlite pipes. Most diamonds are found either within these pipe-like structures or within sediments in rivers after the original rock has been eroded. Diamonds are the hardest material on the planet so are very resistant to erosion and transport (although a good whack on a diamond in the wrong place can shatter it!).
Diamonds come in a wide array of colours from white to black, yellow to blue and all the colours in between. Most people would probably be surprised to discover that a large amount of diamonds that are mined are not of gem quality at all and are used in industry as abrasives and in high-speed cutting tools.
Diamonds are valued based on the 4 C's, Colour, Clarity, Carat and Cut.
Diamonds are rated on their colour on a scale of D to Z, which D being the whitest and most pure colour and Z being a strong yellow colour. Both ends of the spectrum fetch high prices as a very good diamond with a strong yellow colour (known as fancy yellow) can be as prized as a white diamond, Tiffany yellow diamonds are world famous for their rich colours and high prices! Other famous coloured stones include the blue Hope diamond famed for the bad luck it gives its owner and the large pink diamond the Darya-ye Noor ('ocean of light') which is one of the largest cut diamonds in the world.
The Tiffany yellow diamond was only warn by two people, the second was Audrey Hepburn in publicity shots for 'Breakfast at Tiffany's'
Like many minerals Diamonds contain inclusions which are small minerals that grew before the diamond and have been surrounded by it. In some gemstones, such as emerald, inclusions can add to the appearance of a stone as long as it doesn't compromise the structure, however the most highly prized diamonds are those free from inclusions. Many diamonds on the market are classed as having visible inclusions under a 10x hand lens but these inclusions will be invisible to the naked eye and won't effect the sparkle or 'fire' of the stone.
The weight of a diamond is a big deciding factor on the price of a stone although the combination of all 4 C's is taken into account when it is valued. Diamonds are weighed in carats which is a weight based on a carob bean. Because diamonds are dense materials a one carat diamond will naturally be smaller than one carat of a less dense mineral such a quartz. Large carat weights of diamonds are rare and rarely come on the market, many of which are in private collections such as the Koh-i-Noor (which means 'mountain of light' in Persian) which is in the crown Jewels of the British Royal family.
The cut of a diamond is the final important factor when valuing a diamond, and indeed before the cutting even occurs. There would be a temptation to maximise the amount of diamond used when cutting a rough stone but this can lead to a poorly cut stone of low worth. A good cut will reflect the maximum amount of light back out of the stone giving a good 'fire' and that well-known diamond sparkle. A poorly cut stone will not.
Preference of cut is a personal taste with the most popular being the brilliant cut, well known for its use in solitaire engagement rings. Other cuts include the Princess and Radiant cut which are two square shaped cuts, fancy brilliants which have similar arrangements of the facets with the overall shape being anything, although hearts are popular. Marques and Pear drop cuts are often seen on earrings (although the yellow diamond that recently sold at auction was a pear cut yellow diamond). Other, more specialised cuts are also used either to maximise material used or to hide flaws in the stone.
Perfectly symmetrically cut brilliant diamonds will display the 'hearts and arrows' phenomenon which requires high precision making such well cut stones extremely valuable.
Well, I hope you didn't mind indulging me a little bit of visual beauty this time. I hope you find diamonds as interesting as I do, they are truly one of the world's great wonders.
Diamonds are a girl's best friend but a boy needs to befriend his bank manager to buy one!
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