4.0mm Round Lab Created Blue Spinel

Blue is a really difficult colour to maintain when exposing to heat.  A lot of the blue stones I've tested change colour to various shades of brown, not quite what you're after.  I have finally found a fantastic deep intense blue in these LC Spinel that are heat sound.  They have been heat tested for kiln firing to 850 degrees C  and also torch firing.  Remember to let cool naturally as quenching in water would shatter the stone. Price is per stone.