Disregard my message on Wednesday, It does look as if this stone will be 200 tonnes. See
http://www.thisiscornwall.co.uk/displayNode.jsp?nodeId=79373&command=displayContent&sourceNode=78925&contentPK=8744547
Can anybody tell me what size a 1 ton lump of granite would be?
The uprights of the Stonehenge Great Trilithon are 40 tons each. The whole Trilithon totals 90 tons.
A 200 ton lump is more than I, the taxpayer, am happy to pay for if I'm expected to, unless there's a very good reason for it.
The Grand Menhir Brise at Locmariaquer was 250-350 tons. There's a reconstruction here:
http://www.lessing4.de/megaliths/reconstru.htm
Pretty darn big...
Concrete is about 2.5 tons per cubic metre. Granite is probably a bit denser, say 3 tons per cubic metre, so a block of granite 70cmx70cmx70cm would be about 1 ton (or tonne).