5.5mm Low Temp Ruby/Spinel Beads
These beads are made with lab grown corundum & spinel, corundum aka ruby/sapphire.
They are strong but not as thermally resistant as quartz, so use with low temps to preserve them the longest. these will not last forever but with care, should last a while.
CFL corundum #45 will shift from a lake green to shades of purple
CFL corundum #46 will shift from a light grape purple to deeper shades of violet/lavender
Both shades of red ruby are UV reactive
the variety in price per color reflects the cost of raw materials used