Another great contact I've made through Twitter in the last few months is the Aspex Corporation in Pittsburgh, PA. Aspex has been in business since the early '90s and they have embraced social media with a savvy and confidence that makes them stand out. The Aspex Corporation makes Scanning Electron Microscopes among other things and that a company in a very technical field and a kitchen designer could strike up a casual acquaintance is a great example of the expansion and simultaneous contraction of the world made possible by social media. A scanning electron microscope (or SEM) is an instrument for visualizing the surfaces of objects and materials not possible through ordinary optical microscopes.

Toward the end of July 2008, The New York Times ran an article in its Home and Garden section about the supposed dangers posed by radioactive granite counters. Their piece was prompted by a concerted effort by an industry group that represents solid surface fabricators to prop up their dying product category by any means they could. So they took a bunch of information about normal, background radiation; dropped all context and pretense of real science, and embarked on campaign of fear-mongering and misinformation. Their efforts found fertile soil at the Home and Garden desk at The Times and so a public health threat was born. Never mind that wasn't a threat to begin with.

This is Absolute Black. It is always labeled and sold as granite but it isn't granite. It's a mineral called gabbro. When magma gets trapped in a single layer underneath the earth's crust, it will gradually cool and form gabbro. Now if the same material were to be pushed up from below under great pressure, it would form granite. But then again, if that magma were to come in contact with water it would turn instantly into basalt. Are you still following me here?

That sounds like the name of a Do-Wop band. So since I touched on igneous rocks in general and granite in particular yesterday, today I want to talk about the metamorphics. The blue section in this diagram shows how metamorphic rocks end up back on the surface of the earth after their time spent below ground. That blue section is how we get three common metamorphic rocks used in homes: marble, quartzite, soapstone and a fourth, mysterious stone called serpentinite.

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.

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.

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.

Yesterday, I devoted a lot of space to answering a reader question about something she thought she'd heard about granite counters emitting a gas that gave her a headache and could make people sick.

She didn't know the words, but what she was asking about was Radon coming from granite counters. Yesterday's column defined the terms atom, radiation, radioactivity and radon.Now that I've established those terms, I'm going delve back into the topic and write about how Radon gets into granite counters and whether or not it's dangerous.

Help! A couple days ago on our local news channel, they was talking about granite counters put off a dangerous gas. Studies showed people was having headaches and a few other symptoms. I forgot the gases that it puts out. I missed most of this, but I get headaches all the time since we moved into our new house. We have granite counters. Do I have radon and is that what's giving me headaches? I read you every day. Thanks.

Nanoseal is a new product that uses a new technology to render all natural stone waterproof and impervious to stains. This product is for use on granite, marble, travertine, limestone and any other surface you can think of. Imagine, now you can make a shower enclosure out of travertine and never worry about what the water's doing to the stone. Amazing. This process also overrides any concerns anyone could ever have about marble. The thing I love most about marble, it's living and moody nature, can be circumvented completely with a single Nanoseal treatment.