metallic glazes

I have seen metallic glazes that are very impressive. One was very brilliant,
looking like a black chrome mirror. Another was a very shiny metallic orange
color. Then there are the semi glossy gun metal glazes, raku glazes, and
finally metallic lusters.

I am interested in developing a set of metallic glazes, however I don't have a
good idea on where to start. I will be firing to cone 6 in an electric kiln
(oxidation).

First, I am wondering about the effect of reduction on metallic glazes. Raku
and metallic lusters are generally most successful in reduction environments.
The lusters for oxidation environments contain local reducing agents. Has
anyone currently doing raku had a metallic surface develop without the post
firing reduction?

Second, I am wondering about the temperature requirements of metallic glazes.
Both raku and metallic lusters are traditionally low fire techniques. I know
metallic glazes can be made at cone 6 by overpowering the glaze with manganese,
resulting in bronze or coppery colors. Does anyone know if I can get a
metallic surface at cone 6 that has the brilliant blues, greens, and reds?

finally, Is anyone familiar with cone 6 or higher glaze that does not rely on
manganese for the metallic effect?

Any help is greatly appreciated
- Mike