What can these colourful grains be? Clearly a variety of rock-types, quite angular but showing signs of smoothing and abrasion. Some limestones? Green chert, perhaps? Dark basalt? And turquoise?
Well, actually, no. A colleague where I’m working just returned from taking his 82-year-old mother on the “Mini-Haj” in Mecca (he had spent some time in advance getting into shape so as to be able to push her wheelchair the necessary distances). When he saw these in Mecca, he thought of his geologist friends and brought them back – they’re candies/sweets, chocolate inside, a sugar colourful glaze on the outside. And they are granule-size, not sand. So this post is entirely a hoax, a bit of perhaps much-needed fun – and they are good!
Sold in the USA as well (but Google does not find them in UK), in this form and also as beach stones: http://www.fancyflours.com/candy-rocks-chocolate-beach-pebbles.html
One would like to know the fluid dynamics/chemistry by which their surface and color are controlled; is it similar/analogous to plutonics? Could it be a model?
Hi Michael. Back after a long research project in less reasonable disciplines. And less amusing ones: good to find you as ever light of heart and visually attractive. Eye candy, as it were.
Posted by: Richard Bready | March 20, 2011 at 08:24 AM