Introduction
One of the obstacles to putting together EarthCaches for the enjoyment (hopefully) of others is terminology.
It's not just that some words which have one meaning in common vernacular have a quite different meaning in proper geologist speak, it's also that the preferred or accepted terminology frequently changes too - as will be evidenced later in this EarthCache narrative.
This EarthCache takes you to location where you can see examples of igneous and sedimentary rocks but it's only the igneous rocks you really need to pay attention to 
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Logging Tasks
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Based on your observations at the given coordinates and the information on the cache page, please tell me:
- Describe the microstructure of the granite used in the monument - particularly in terms of crystal size and colour.
- Some parts of the granite used in the monument have been polished and others have not. Is it easier to see the microstructure in the polished or the unpolished parts of the rock?
- Behind the monument, at ground level, there's a lump of limestone with two tablets of igneous rock attached - one to the front and one to the rear. Describe the microstructure of that igneous rock - particularly in terms of crystal size and colour.
- Is the igneous rock on both sides of the lump of limestone the same or are they different?
- Would you say the igneous rock tablets on each side of the lump of limestone are granite or something else and how do you arrive at your conclusion?
- Optional task: feel free to add any photographs of your visit that do not show the specific features from the logging tasks - no spoilers please. In the interests of allowing everyone to experience the EarthCache fully for themselves obvious spoiler photographs will be deleted.
Background
Granite is a well known igneous rock which many people recognise because granite is used to make many objects that we encounter in daily life. These include counter tops, floor tiles, paving stone, kerbing, stair treads, building cladding, and cemetery monuments. Granite is used all around us - especially if you live in a city.
There are though numerous other igneous rocks which are used in similar ways and which are generally, but incorrectly, described as granite. One reason why many igneous rocks get lumped together under the general description of granite is that the microstructures of those different rocks share significant similarities with with microstructure of granite.
Rock Microstructure
Previously I'd have said It's important to remember, when we talk about texture here we're not talking about how the rock feels to the touch, we're using texture in the geological sense to describe the size, shape and arrangement of the crystals in an igneous rock .
Well it seems now that texture has fallen out of favour and the term microstructure is preferred in modern geological literature. Not a massive change - modern texts will refer to microstructure where older texts would refer to texture. Personally I think microstructure is a more appropriate and meaningful term in this context anyway.
So, the microstructure of an igneous rock is one of the measures geologists use to classify and name the rock, with crystal size being a key aspect of that classification.
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Fine crystals (< 1mm) - typically form the bulk of igneous rocks such as rhyolite and basalt, among others.
Crystals in this size range are mostly too small to be seen with the naked eye. The term aphanitic, previously used to describe the texture (as it was previously known) of rocks composed of such crystals, is now largely defunct.
The tiny crystals in this rock tell us that the magma it was formed from must have cooled relatively quickly and solidified before the crystals had time to grow large enough to be seen with the naked eye, which in turn tells us that the magma this rock was formed from cooled at or close to the Earth's surface.
Igneous rocks which form in this way are known as extrusive igneous rocks.
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Medium (1mm < 5mm) and coarse (5mm < 3cm) crystals - seen in igneous rocks such as granite and gabbro, among others, previously described as having phaneritic texture.
Crystals in this size range are clearly visible to the naked eye. When the crystals are all roughly the same size the rock can be described as equicrystalline.
Rock crystals tend to grow very, very slowly - which means it takes a long, long time for the crystals to get to this size. This tells us that the magma which these rocks were formed from must have cooled very, very slowly at considerable depth beneath the Earth's surface.
Igneous rocks which form in this way are known as intrusive igneous rocks or plutonic igneous rocks (plutonic from Pluto, the Roman god of the underworld, as opposed to Mickey Mouse's dog).
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Very coarse crystals (3cm and above) - seen in igneous rocks such as pegmatites
The names of igneous rocks are usually dictated at least in part by the specific mixture of minerals they are made of. With pegmatites that isn't the case - it's all about the extreme crystal sizes.
Most pegmatites have a mineral composition similar to that of granite with abundant quartz, feldspar, and mica and these are sometimes referred to as granite pegmatites. However, compositions such as gabbro pegmatite, syenite pegmatite and any other plutonic rock name combined with pegmatite are possible.
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Porphyritic - a mixture of fine and coarse - from the Greek porphúra meaning purple.
In the past the term porphyry applied exclusively to a specific type of purple coloured rock. Purple was the color of royalty, and the imperial porphyry was a deep purple igneous rock with large crystals of plagioclase feldspar.
Porphyry later came to be used as a term to describe rocks with the same sort of microstructure as that purple rock i.e. large crystals of feldspar surrounded by a groundmass of much smaller crystals, regardless of colour. The distinctively larger crystals in a porphyritic igneous rock are known as phenocrysts.
Igneous rocks with porphyritic microstructure are formed when a column of rising magma is cooled in two stages. In the first, the magma is cooled slowly deep in the crust, creating the large crystal grains (phenocrysts) with a diameter of 2 mm or more. In the second and final stage, the magma is cooled rapidly at relatively shallow depth, resulting in the much finer crystals of the groundmass.
Colours are important too
Granites tend to be light coloured rocks because the minerals which make up their bulk tend to be light in colour - pinks, whites and even colourless quartz, combined with a peppering of darker minerals such as mica or hornblende.
Other igneous rocks such as basalt and and gabbro, being made up mainly of dark coloured minerals tend to be dark coloured rocks.
It is essential therefore, when trying to identify an igneous rock that we give full consideration not only to the size and arrangement of the crystals the rock is made of but the colour(s) of those crystals too.
If you've carefully read and digested the information from this cache page your tasks at the cache location should prove relatively straight forward, although you may wish to take a printed copy of the page with you so that you can check your answers while there 
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Please submit your logging task responses before posting your log.