On Monday, July 22, 2013 12:28:30 PM UTC-7, Michael Press wrote:
> In article >,
>
> "Julie Bove" > wrote:

> > I had a really good marble mortar and pestle. But when we move here, the
> > pestle never arrived. I kept the mortar for a while, hoping it would show
> > up. Never did. My new one is not as good. It's black. Not sure what it
> > is made of.
>
> On the Moh scale of harness marble is 3, agate is 7.
> No contest. Basically everything harder than agate is
> diamond or some form of aluminum oxide. In addition,
> marble is porous making it impossible to clean out old
> oil that seeps in. You will never get that stale black
> pepper oil out of your marble mortar. And marble is
> subject to chemical attack. Better one those white
> porcelain sets.
>
>
>
> Moh Scale Representative Gemstone
>
> 10 Diamond
> 9 Corundum (Ruby, Sapphire)
> 8 Topaz
> 7.5 Beryl (Emerald, Aquamarine)
> 6.5-7.5 Garnet
> 7 Quartz (Amethyst, Citrine, Agate)
> 6.5 steel file
> 6 Feldspar (Spectrolite) granite
> 5.5-6.5 most Glass
> 5 Apatite
> 4 Fluorite
> 3 Calcite, marble also a copper penny
> 2.5 Fingernail
> 2 Gypsum
> 1 Talc

We got a big heavy one from Crate and Barrel on closeout several years ago. I believe it was for making guacamole. Seems similar to this:

http://www.casa.com/p/cilio-granite-...-pestle-570402

Granite supposedly ranks between 5 and 7 on Mohs hardness, so it is better than marble, and might even be as hard as agate.