Chris Berry talks about the stone

About the Stone

Limestone: Indiana Grey and Buff - no grain 
The 2 colours come from the compaction of different periods of time. Both colours basically carve the same, both are chalky and easy to control. It's a stone that is not very hard on your chisels because of its chalky characteristic. Dampening the stone softens it some-what, and keeps the fine dust down. If the stone is wet it will appear darker and will lighten at it dries. It leaves you free to bring out what you feel is within the stone without a visible grain. When carving with limestone you should always install it with lime mortar as natural mortar with limestone will not stain the object nor will it create erosion. This is a very desirable stone to carve.

Sandstone: Berea
It has characteristics opposite to that of limestone. It is brutal on your chisels. The tools will constantly require sharpening as the stone is very abrasive. 

You are controlled by the grain some-what but it carves well. Keeping the stone damp is best, as this makes the stone a little softer. It is always best to carve with the grain and not against it, as you will notice that you have far more control and less chance of destroying the countless hours of work you have put into the piece that you are working on. When the stone is damp it allows it to come away like sugar granules and will also helps to keep the dust down. 

With evolution has come the advent of pneumatics, which has made cutting out a large stone more productive. What may take me two weeks to carve by hand with regular chisels can be done in a day with air chisels.

Periodically I found that I required a chisel of a specific length and width that was available, so I spent time reading books on blacksmithing to help me understand steel and its applications and I now forge my own tools. It is important to keep
your chisels sharp at all times, in order to have better control of the stone and put less stress on your body. If you allow it, the stone will speak to you through your chisels beginning with the flaws in the stone, the voids in the stone, the fossils you
will see, cracks that will appear, fissures that become noticeable and the density of the stone.

Soapstone: 
You will get a very aesthetically pleasing result with soapstone. It is a pleasure to work with plus, it give you a chance to use other tools besides your maul and chisels. 

Queenstone: 
This is a hard, very dense fossilized stone that is exceptionally hard to carve. Always ensure when working with this type of stone that you wear safety glasses as the fossils are as sharp as shards of glass and are capable of doing a lot of
damage when they fly off the stone. To bring out the fossil colours, grinding is required, using coarse to very fine wet paper. It is beautiful when polished and showing multi-coloured crustaceans. 

Any stone that you work with, you will find very unforgiving!

Moulding Clay:
Moulding clay is another enjoyable medium to work with. Clean up is easy and you can let your imagination run free. Not all the ideas you may experience when working with clay are transferable to stone. When you notice that there is not
enough fullness in a cheek of your character you can easily add extra clay but his is not so with stone. In stone, if the cheek is a little flat, it may require changing the whole face.

Recommended reading "The Pillars of the Earth" by Ken Follett - As a new age dawns in England's 12th Century, the life of a stonemason is revealed as he builds a mighty Gothic cathedral, setting the stage for a story of intrigue, power,
revenge and betrayal.