A colorless and translucent to transparent celestine blade. Of particular interest is the 'saw tooth' edge. That this is celestine and not barite or anhydrite was determined by specific gravity. Recorded specific gravities (Mindat) are celestine = 3.96-3.98, barite = 4.50, and anhydrite =  2.98. The measured specific gravity is 3.87, a good fit for celestine. Celestine is uncommon (or just routinely overlooked) at Naica: of the 1025 mineral specimen photos for this locality hosted at Mindat, only one is of celestine. Complete all around (a floater), with very minimal edge wear.