Pyramid Ice Crystal Halos Over Finland . ... This actually happens when a nearly transparent sheet of pyramid shaped ice crystals falls from the sky in a common orientation. ... An amazing display of pyramid ice crystal halos was captured on June 5 above Tampere , Finland . Visible above are very usual sun halos of 9, 18, 20, and 23, and 24 degrees. In contrast, thin and flat falling ice crystals will produce a halo of 22 degrees only. ... NASA Web Site Statements, Warnings, and Disclaimers . ...