On 03/14/2016 11:30 AM, Huw Saunders wrote:
> As with the other very heavy metal
> gold, there are not very many stable compounds of mercury.

A bit off topic, but there are very many stable compounds of mercury, 
some of which may be in your teeth.

Wiki says this on vermilion:

>
Vermilion has one important defect; it is liable to darken, or develop a 
purplish-gray surface sheen.[9] Cennino Cennini wrote, "Bear in 
mind...that it is not in its character to be exposed to air but it is 
more resistant on panel than on walls since, when it is used and laid on 
a wall, over a period of time, standing in the air, it turns black"[13] 
The darkness is not a result of the vermilion itself, which is very 
stable, but is caused by impurities and adulteration of the pigment.
<

Didn't know about fib{er/re}glass pencils; am on my way to buy one right 
now, so thanks!

best,
  Stuart


-- 
i still have a very small website
http://dustyfeet.com

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