Powder coloring pigments - oxides mainly

[RogueRose]

I've been looking at various oxides and powder pigments which don't seem to be labeled as to what they are such as ultramarine blue. I've found that a lot of the colors are based on iron oxides and I know cobalt makes a blue and copper possibly makes a blue oxide.

Does anyone know what ultramarine blue pigment is made from? Is it a metal oxide or something?

I'm looking for the three primary colors and blue seems to be the most difficult.

Does anyone know if pottery pigments can be used for soaps?

 

[Saponista]

If you look at page 25 it says ultramarines are found in gemstones in nature (lapis lazuli) but the ultramarines you buy are manufactured.

http://www.soilassociation.org/LinkClick.aspx?fileticket=0fUUx1yUjRI=&tabid=353

If you look at the production section on Wikipedia, it tells you what ingredients go into producing the manufactured forms

http://en.m.wikipedia.org/wiki/Ultramarine#Production

 

[MorpheusPA]

Ultramarine blue is, as Saponista noted, chemically identical to lapis lazuli.

The other names for the blue colorant are Prussian blue or Parisian blue.

I've no idea if pottery pigments can be used, but suspect it would be on a case by case basis anyway.

For soap, the primary colors in the oxides/ultramarines are:

Red: Iron oxide (brick red)
Yellow: Iron oxide (golden yellow)
Green: Chromium oxide (Kelly green)
Blue: Ultramarine blue (royal blue)
Black/Darkener: Iron oxide (black)
White/Lightener: Titanium dioxide (white)

You can get plenty of other tones in FD&C colors if those won't do, but many FD&C colors will bleed over time in soap.