Ivor and Olive Lewis on thu 30 dec 04
Reference to "Opal Blue" as a descriptor for a glaze has a nice poetic
ring to it but it raises a questions in my mind.
"What is causing the Colour?"
Is because the glaze behaves like a Silica Gem Opal with respect to
light? Is it due to colouration by one of the metallic ions, as is the
case for Cobalt Blue ? Is it caused by the development of a second
phase by the Boron content in recipes?
Finally, why not Opal Red, Opal Violet, Opal Green, Opal orange, Opal
yellow or even Black Opal ?
Best regards and a Happy New Year to everyone
Ivor Lewis.
Redhill,
S. Australia.
Cindy on thu 30 dec 04
Hello, Ivor
Opal Blue (the fritted one--can't speak for the other version) does have a
beautiful, deep, opalescent look. No fiery sparkles, alas.
Best wishes,
Cindy in SD
PM
Subject: - Opal Blue Glaze
> Reference to "Opal Blue" as a descriptor for a glaze has a nice poetic
> ring to it but it raises a questions in my mind.
> "What is causing the Colour?"
> Is because the glaze behaves like a Silica Gem Opal with respect to
> light? Is it due to colouration by one of the metallic ions, as is the
> case for Cobalt Blue ? Is it caused by the development of a second
> phase by the Boron content in recipes?
> Finally, why not Opal Red, Opal Violet, Opal Green, Opal orange, Opal
> yellow or even Black Opal ?
> Best regards and a Happy New Year to everyone
> Ivor Lewis.
> Redhill,
> S. Australia.
>
>
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