(Stevie) I have two quince bushes in my garden and at this time of year they drop their fruit which are yellow and somewhat smaller than a cricket ball. One year I thought I'd have a look at them. They're as hard as nails and if you really chucked one at someone it wouldn't do them a lot of good. Heavy equipment is needed to open one then you find a large cavity full of seeds and a tooth-breaking outer part with a pH of about 0 like conc. sulphuric. I would have more success making jam out of boiled-up breeze blocks than I would out of these buggers.

Have any of you participated in the delightful sport of cracking macadamia nuts? This a tough game involving plenty of hilarity for spectators, loads of frustration for the nominated cracker and much exuberance exhibited by all when the aim is achieved.

(Dujon) Macadamia? Isn't that what road surfaces are made from? Not surprising they're hard to crack. Maybe that's a British joke.