stone carbon - what's it made from

[Watershed]

Ok so I know what it is - a form of activated charcoal.
But is that 'stone' as in what you get in the middle of olives, peaches and plums or 'stone' as in some kind of mineral source.
Watershed

[Billy Joe Jim Bob]

Activated stone carbon is made from bituminous coal, soft coal that isn't really good to burn for heat. Other activated carbon can be made from coconut hulls. Becareful when purchasing for distilate filtration, as some of it is acid washed and may contain "nasties". Check out generalcarbon.com for more information...BJJB

[Watershed]

Cheers. In other words it's low grade coke. I buy mine from an online home distiller supply shop thinly disguised as a home brew shop, it's amazing what you find under the 'water purification' section - including alcometers.