This large icicle formed during the January 2024 Pacific Northwest winter storm. It is over one year old in this photo, and was the youngest crystal in my collection.
The poor cut on this gem may be the reason for the large black 'window' seen through the table facet. While the surface finish is excellent, an alignment error must have occurred while transferring the stone from pavilion to crown cutting orientation.
Imperfection is a fascinating recurring theme within gemology. Like other fluorescent minerals, Calcite only glows like this if it contains some impurity..
LYSO (Lutetium–yttrium oxyorthosilicate) under 365nm UV light. LYSO is a scintillator crystal, used to convert x-ray photons into visible light for medical imaging, but also glows brightly even under a dim blacklight!
Ruby + Ultraviolet light (365nm). The wavelength is hard to see and causes bright red fluorescence in the crystal, making this wonderful glowing effect!
