Now, however, the mottled soaps, blue and grey, are produced by working colouring matter, ultramarine for blue, and manganese dioxide for grey, into the soap in the frame, and mottling is very far from being a certificate of excellence of quality.
All of the eight point areas have mottling and speckling.
H. cucumerifolius, the Miniature Sunflower, is a good annual, growing from 2 to 3 feet high, usually with purple mottling on the stems, the leaves thin, and bright apple-green.
McKay eventually discovered that this "mottling"-as he called it-resulted from high levels of naturally occurring fluoride in the drinking water.
The difference between the amount of fluoride that is beneficial and the amount that can cause mottling is only two to four-fold.