william melstrom glass - About GOOD MACRO CRYSTALLINE GLAZES are mesmerizing. They shimmer and shift much like holograms do, and are literally three dimensional. They develop "growth rings," halos, star-bursts and "auroras," which record changing conditions within the kiln. Chance and serendipity play a great part in crystalline-glazed compositions. I do not "seed" the crystals on the porcelain, nor can I see them growing in the kiln.