- 1735, John Barrow, Dictionarium Polygraphicum: Or, The Whole Body of Arts Regularly Digeſted, unnumbered page,
- There is also a factitious jeat made of glaſs, in imitation of the mineral jeat.
- 1758, Gentleman's Magazine and Historical Review, Volume 28, page 10,
- To make a Grey Colour.
- Take iron ſcales, a little criſtal, and ſome ſmall quantity of jeat, grind theſe well together upon a painter's ſtone; the more jeat ye take, the ſadder the colour will be, and likewiſe the more criſtal you put to it the lighter.