Dyed Alum or Dyed Quartz (Ornamental Crystal)
Silicon Dioxide (SiO2) or Potassium Alum [KAl(SO4)2·12H2O]
Rock Type: mineral

Physical Properties
Hardness: 7 (if quartz) or 2.5 (if alum); Color: Synthetic neon purple, blue, red; Luster: Vitreous; Crystal Structure: Trigonal/Hexagonal or Octahedral; Cleavage: None/Poor.
Formation & Geological History
These specific specimens are lab-grown or treated. Natural quartz geode bases are often used and then dyed with vibrantly colored pigments or coated in a laboratory setting to create 'aura' or 'neon' effects.
Uses & Applications
Primarily used as home decor, 'healing' crystals, gift shop souvenirs, and as educational tools for children.
Geological Facts
The neon-bright, uniform colors seen here do not occur naturally in these saturation levels; they are the result of artificial dyeing processes where pigments are absorbed into micro-cracks or natural crystal pores.
Field Identification & Locations
Identify in the field by checking for unnaturally bright colors that follow cracks. Natural amethyst or quartz will have more subtle, varied color zoning. These are commonly found in tourist gift shops rather than mines.
Identified on: 5/3/2026
Mode: Standard