Help - Can't Tell The Difference Between Black Marble and Black Granite

[Peter Zacarelli]

I ordered both black marble and black granite at the same time. I have never worked with either before. I am looking at the pieces that were sent and for the life of me I can't see any difference between any of them (16 pieces, suppose to be 8 of each) other then some are thicker then the others. Is there some way to detemind which is which. Sorry if I sound like a moron but I am serious.

Thanks for any help that may be provided.

[Richard Savidge]

Black granite has noticeable silver flecks running through it black marble does not.

[Carol VanArnam]

Peter- if you figure it out let me know. I always get confused myself......

[Peter Zacarelli]

Thanks Richard, I do have some with silver flecks running through.
It seems kind of crazy, you would think you could tell the difference right away but just looking on them I couldn't except some do have the silver flecks. I was beginning to wonder if my order was correct or not.

Again, thanks.

[Greg Funk]

You should be able to scratch the marble with a knife but not the granite. Also vinegar should fizz with the marble dust you scratch off with your knife.

Greg

[Frank Corker]

Greg is right. Granite is the 3rd hardest natural material only next to diamonds and rubies it has an erosion factor of 1/16 inch for every 1000 years outside. Marble can't match it for strength and durability. That said, Rome seems to have an awful lot of old stuff that has survived for a long time

[Mitchell Andrus]

EVERYONE knows......

Marble is metamophic rock and Granite is ignious rock.

Plus, Marble will dissolve in acid.

[Larry Bratton]

That's easy for you to say

[Mark Rios]

The black marble will be the round one.......................

[Gary Hair]

Just don't take it for "granite" that you can always distinguish marble from granite...

[Belinda Barfield]

Technically, most black granite isn't granite at all. It's basalt.

[Bill Cunningham]

Marble of any colour is a pretty soft stone, that also turns white when struck by the laser beam. This is why it produces great looking photographs. While Granite will simply have the polished surface removed by the laser, and the resulting etch (it's not really engraving) will be the same colour as the natural granite (flip it over and see the non polished side) it does not bleach like marble, and as a result the contrast is not as great and the resulting etch can always be wiped down with some white oil paint on a cloth to brighten it up..