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GeneralPegmatites as ornamental stones

25th May 2018 06:19 UTCLuís Martins 🌟

How often pegmatites are used as ornamental stones, from a commercial point of view? I don't mean the odd stone being prepared by a collector, but a commercial operation that mines a pegmatite to produce ornamental stone (slabs for counters and paving, for example).

I've just saw an example of it in the Mumbai airport international terminal (no photos, unfortunately, as it was in yhe passport check area). Beautiful, simple pegmatite, with big black miss, and even a small beryl.

25th May 2018 10:12 UTCJohan Kjellman Expert

rarely-never, since pegmatites in general are heterogeneous non-coherent rocks, prone to fall apart because of large grain size, cracks, and perfact cleavage of several constituents.

cheers

25th May 2018 10:40 UTCJhonatan Gomes

Have a product called "branco delicato" ( at portuguese), used in ornamental Stones

25th May 2018 15:54 UTCPaul Brandes 🌟 Manager

Agree w/ Johan.

No one specifically mines pegmatite for its ornamental value that I know of. Are you sure what you saw wasn't just a large grained granite (but too small to be classified as "pegmatite")? Those types of material are used in countertops, wall displays, etc. If it was truly a pegmatite, then some sort of stabilisation would have to been done to keep it together, otherwise it would fall apart rather quickly.

25th May 2018 16:09 UTCTony Albini

Luis,

I had some granite pegmatite pieces which I used as ornamental pieces to hold down tarps in my yard. These pieces were solid enough to hold up under varying weather conditions. One quarry in Thomaston, CT had large pieces of orbicular granite that was beautiful when polished. A cemetary in central CT once had gravestones carved from massive rose quartz that probably came from the nearby Howe #1 quarry. This gravestones unfortunately later disappeared. As everyone else has said, I know of no peg being worked just for ornamental pieces.

25th May 2018 19:27 UTCJolyon Ralph Founder

I see a lot of slabs of granite in building, paving stones, etc in Russia that have pegmatite veins. I always assumed this is because they're using lower quality material to save costs because most customers would want consistency of texture & look.

26th May 2018 00:40 UTCDana Morong

A neighbor of mine has a kitchen countertop made of a beautiful pegmatite - with quartz, feldspars (both K-spar and albite, apparently), muscovite, black tourmaline, beryl - a beautiful countertop. I had a post here some time ago (might have been a couple of years) and I wrote up a discussion about it. I did not then have a camera, so could not then take a photo of it, but now that I have one (I've got to learn how to use it) I am glad to get this reminder.

I also have wondered how such a slab could be cut, transported, installed, without its breaking, as the crystals in this thing are truly enormous. When I do get around to taking photos, should I use silverware as a scale, or just use a regular ruler?

26th May 2018 16:43 UTCDonald B Peck Expert

Hi Dana,

I would suggest a silver spoon! Like you, I can't imagine, cutting, transporting, and installing that counter top without it falling apart. Perhaps they used the (common?) technique of cementing slender steel rods in saw cuts on the lower side.

Don

26th May 2018 17:25 UTCDana Morong

The post was titled "Indoor Imported Life-sized Mineral Deposit Display" posted December 28, 2013, although the text starts with 30 Nov 2013. I really have to learn how to use that digital camera! (sunlight and other projects have lately lured me outside, instead of inside looking at the handy manual in pdf).

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