Monday 19 November 2012

Geology and gemstones: Sunday Stamps


The challenge this week on Viridian's Sunday Stamps was to share a stamp featuring something related to geology. I get pretty excited about rocks these days, so I thought this was quite a wonderful, broad topic. Australia has issued several stamps featuring Uluru (formerly Ayers Rock), which is arguably the country's most famous geological marvel. A sandstone monolith, that turns red at dawn and dusk, Uluru is magnificent.



However, given the scope and possibilities for the theme 'geology' I was hoping that I could come up with something a little bit more exciting than the standard Uluru stamps. (That said, there is nothing 'standard' about Uluru itself. It is an awe-inspiring and magical place, and it deserves its iconic status.)


Anyhow, it turns out we don't celebrate rocks (or geology) enough in our stamps issues. I wanted to find a cool stamp with some sort of graphic representation of tectonic plates or volcanic eruptions, or something. But no. What I did find was opals and gemstones. Sort of cool, but not earth-moving, geological-time encapsulating, rock strata-depicting, mind-blowing cool. Just 'reasonably-pretty' kind of cool.

These stamps featuring the opals were issued in 1995 and were the first 'holographic' stamps issued by Australia Post. I was worried that opals wouldn't fit with the geological theme if they are minerals and not strictly speaking rocks, but it turns out they are actually classified as 'mineraloids.' And according to that most reliable source, Wikipedia, they can be found in the fissures of almost any rock.


My scientific education is sorely lacking, but from what I gather minerals are not rocks. Rocks are composed of minerals. So therefore it is fine to include opals in a post about geology, which in part is about rocks (but is not the study of rocks, because that is petrology).

Anyhow, moving right along. Opals are also Australia's national gemstone. The first time opals featured on a stamp was in 1973 when the 8c opal stamp was part of a definitive issue, which combined the bizarrely unrelated topics of 'gemstones and marine life'.





I haven't heard of chrysoprase before, but it looks a hell of a lot like Kryptonite, don't you think? Gemstones are basically pretty minerals. The earth is composed of rocks, which are composed of minerals; and whilst petrologists study rocks, and mineralogists study minerals, geologists study the earth. Minerals are cool, but volcanoes and tectonic plates are cooler. The end.

12 comments:

  1. what a number of great stamps! had no idea Uluru turned red at those hours...
    Kryptonite...now that reminds me of Superman!

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  2. I think the red rock Uluru is very interesting. I have an opal ring that was my grandmother's, and my mother always called it a "fire opal."

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    1. Yes- Uluru is definitely interesting. It is a special place. The stamp packet descibes opals as "the fire in the stone" - so it makes sense that your Mother called it a fire opal.

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  3. A series of stamps that are well worth seeing. My geology lessons all came back to me.

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  4. Another excellent blog, sadly I remember when the Opal stamps were released - showing my age a little.

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    1. Don't worry Sandra - I remember when the opal stamps were issued too. These stamps are actually part of my own collection - not part of a collection that I have inherited! :) Thanks for reading once again! x

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  5. It is interesting how we see our own landmarks as a little 'mundane', isn't it?! My biggest disappointment when I visited Australia was not getting to see Uluru due to severe flooding. But I did manage to get a couple of lovely opals that I had set into a pendant.

    p.s. I love how pedantic you became with the different studies of gemstones, minerals, rocks. I tend to lump everything together and I wish I knew the differences with confidence, like you do.

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  6. Hi Violet sky! This blog post was me trying to figure all those differences out! Gem stones didn't quite fit with what I imagine geology to be, so I had to try and work out why!
    What a shame you missed out on Uluru. It is spectacular- you'll just have to make another trip to Australia!

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  7. Don't worry you did just fine with your post. And yes gemstones/minerals are part of geology - geology is a big subject. Opals are so lovely and to me, mysterious.
    Thanks for participating!

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  8. I found it difficult to come up with anything this week but you have managed magnificently!

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  9. I like the one with someone holding a big chunk of rock with opal, unusual stamp and quite illuminating. Sandstone is my favourite rock so apart from the mysterious nature of Uluru I would probably quite overexcited if ever I got to visit.

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