Coloured examples are very rare and undescribed1

Iridescent glass H 5.1
Ptolemaic Period
Christie’s The Groppi collection
Sale 7758, part of lot 61
26 April 2012

Gilded obsidian
H 6.8, W 2.1, T 0.4
Late Period
© Musée du Louvre/
Antiquités égyptiennes
#ME 207

Red glass H 4.1 Late Period
© 2009 Musée du
Louvre/Christian
Décamps #N 4313 A

Blue glass, flat back H 3.4, W 1.3
Late Period Art Market

References

1None, Unpublished amulets