13 October 2008

A working definition of granite

The term granite, as it's used commercially, is a bit of a generic term. Now I'm not a geologist but I do have an understanding of the fundamental geology that goes into the dimensional stone that ends up in peoples' homes.


Granite's generally accepted to be an igneous rock composed primarily of silica that's formed in the mantle of the earth as magma gets squeezed between cracks in the earth's crust. As a liquid at that point, the magma tries to rise to the surface. It cools very slowly and under very high pressure then forms what are called batholiths --essentially huge domes that lie below the surface of the earth. These large formations are exposed later through the actions of erosion and thrust faulting. Due to the high pressure under which the magma cooled, the component minerals in it (quartz, feldspar, aluminum oxide, iron oxide, etc.) can crystallize. That crystallization is what makes granite granite.

I bring that up because of this granite right here, commonly called Baltic Brown.


You can see from this close up that Baltic Brown has circular crystals in it. They are in varying sizes but most of them are about two inches in diameter. Those round crystals are made from potassium feldspar and they formed about a gazillion years ago as some magma cooled underneath what is now Finland.

About eight years ago I got into it with a salesperson at a granite wholesaler who claimed that those round shapes were the remains of a stand of young trees that were run over by a lava flow and got fossilized in the process. People who don't understand what they're selling are a pet peeve. Claiming to have fossils in a slab of granite goes beyond not knowing and crosses the line into the idiotic. I don't expect granite salespeople to be able to rattle off the names of the component minerals that make up what they're selling, but some basic knowledge is most definitely in order.


Granite that ends up as counters gets cut into slabs and polished. From the cut stone, you get a really nice cross section of the crystal structure of a particular granite. Those crystals are where granite gets its sparkle and depth. A granite that was left to its own devices as it cooled and formed over the millennia will have a pretty regular pattern and color.

But when granite's actually moving as it cools, or if it runs into water, all sorts of things happen to it. A lot of times granite will run into other kinds of rock as it moves, so it will have incursions of schist and skarn and a host of other materials in it. A lot of times water will make iron oxide gravitate into cracks in the rock. Every component mineral in a granite has its own characteristics and reactions and that non-uniformity is at the root of granite's appeal. The slab below has incursions as well as lines of iron oxide in it.


It's an interesting stone as a stone, but it's a lot to try to pull off in a kitchen counter. I mean, it's pretty loud. Something like that I'd like to hang on a wall to admire. It tells a really compelling story but it's not something I'd want to see in one of my kitchen projects.

Patterns like that granite above are still pretty popular though that popularity has crested and is starting to wane. People are starting to look for other materials to use as counters and that's what I'll be writing about all week. Woo-hoo!

But in the meantime, if you like granite then get granite. Don't believe the stories of its propensity to stain or crack or even be radioactive. Almost every negative you hear about granite is chatter generated by a competitive marketplace. I have never actually seen someone stain or crack a granite counter. Nor have I ever heard of someone who had to reseal their counters. The radon hype is yet another non-story generated by the solid surface people to prop up their decidedly inferior products. Granite is harder than just about anything it will come in contact with and it will continue to look as good as it did the day it went in for the rest of the time you have it.

But let's look at some options anyhow. Tomorrow's going to be marble and the metamorphics.

The rocks in my head, an introduction


Rocks are divided into three categories: sedimentary, metamorphic and igneous. A lot of times these three classes are referred to as phases because each class can morph into each of the other classes over long periods of time. But that's can morph, it isn't automatic.


In English, those three classes can be pretty broadly defined like this: sedimentary rocks are formed by compacted sediment, metamorphic rocks are rocks that are transformed by heat and pressure after they're already formed and igneous rocks are formed by cooling magma. Some examples of sedimentary rocks are limestone and travertine. Some metamorphic rocks are marble, quartzite, soapstone and slate. Finally an igneous rock that's in a lot of peoples' homes is granite.

In the chart above, there's a delineation made between intrusive and extrusive igneous rock. Intrusive means that a formation of igneous rock rises into the earth's crust but doesn't break the surface. Not breaking the surface results in a very particular crystal structure. Extrusive igneous rock breaks the surface and cools quickly when not under pressure. This results in a different structure even if the magma has the same composition.

So there's my breakdown of the three classes of rock. There are examples of all three classes that end up being pressed into use by humanity and I'll be spending some time explaining them further. First up will be granite.

12 October 2008

The Daily Granite



I took a client to a stone yard last week to look at slabs of marble. We went to Custom Marble Works in Tampa. I'd post a link to their website but they don't seem to have one. That's OK though, I love their work so much that it doesn't matter. If you find yourself in Tampa's Ybor City and you're looking for the best place to have marble counters, tables, fireplaces, columns, or what have you made, get thee to 1905 N. 43rd Street. Their number is 813-620-0475.

Custom Marble prides itself on its amazing work and the discerning eye of Rick, who collects some of the most unusual stone slabs I've ever seen. Despite the company name, they don't limit themselves to working in marble. They're equally happy working with granite, quartzite, onyx, serpentine, etc.

My client fell in love with a slab of quartzite and I can't blame her for doing so. But as I explained to her that what we were looking at was neither granite nor marble, but a whole other kind of stone, she seemed a little lost. So I launched into one of my geology lessons and about a half-hour later she knew more about the formation of the earth than she probably wanted to.

I can't help myself sometimes. I'm cursed with a lifelong need to know what things are. So for the next couple of days, I'm going to break my Geology for Homeowners lesson into smaller parts and go through some of the kinds of stone that end up in peoples' homes.

Sunday sale


Smith and Noble's having a sale kids. Head over to their website and click on the Clearance hot key on the left side of the page. They're also running a delivery promo that's great for a last-minute, pre-holiday pick me up. Order anything from their catalog by 12 November and they guarantee delivery by Thanksgiving.

I hate dealing with window treatments and thanks to the pros at Smith and Noble, I don't have to. They even have a wood and DuraWood blind color matching service. No lie. I can specify a color, say it's Benjamin Moore 1545 --Iron Gate. All I have to do is call them ahead of time, send them a swatch and BAM! two weeks later I have custom-sized wood blinds in a custom color. AND they do if for less money than that Levolor crap at Lowe's. They made a believer out of me.



11 October 2008

Saturday stop and think



I've had the Stephen Foster song,
Hard Times Come Again No More rattling around in my head these last few days. Foster wrote it in 1854 in reaction to a string of personal setbacks he lived through. There's something about a line the chorus that's always appealed to me, "Many days you have lingered around my cabin door/ oh hard times come again no more." It conjures such an image for me. Anyhow, if you're not familiar with that song here are the lyrics. It could have been written yesterday morning when the Dow dropped below 8000 for the first time in I don't know how many years.

Let us pause in life's pleasures and count its many tears,

While we all sup sorrow with the poor;

There's a song that will linger forever in our ears;

Oh Hard times come again no more.

Chorus:

Tis the song, the sigh of the weary,

Hard Times, hard times, come again no more

Many days you have lingered around my cabin door;

Oh hard times come again no more.

There's a song, the sigh of the weary,

Hard Times, hard times, come again no more

Many days you have lingered around my cabin door;

Oh hard times come again no more.

(Chorus)

While we seek mirth and beauty and music light and gay,

There are frail forms fainting at the door;

Though their voices are silent, their pleading looks will say

Oh hard times come again no more.

(Chorus)

There's a pale drooping maiden who toils her life away,

With a worn heart whose better days are o'er:

Though her voice would be merry, 'tis sighing all the day,

Oh hard times come again no more.

(Chorus)

Tis a sigh that is wafted across the troubled wave,

Tis a wail that is heard upon the shore

Tis a dirge that is murmured around the lowly grave

Oh hard times come again no more.

(Chorus)

And here's what it sounds like. 

People have lived through far worse than what's going on today. We'll get through it and be better off for having done so.