The two may seem identical by ordinary methods, but a flame test can distinguish them. By scraping the dust of the crystals into a gas flame, the color of the flame will confirm the identity of the crystal. If the flame is a pale green, it is barite, but if the flame is red, it is celestite. Normally barite is not blue, but many specimens of blue barite are often misidentified as celestite. The nice crystals, good luster and attractive blue color make fine specimens of celestite an outstanding mineral for someone's cabinet or display case.
Color is usually blue but can also be colorless, yellow and tints of red, green and brown.
Luster is vitreous. Transparency crystals are transparent to translucent. Crystal Habits include the bladed crystals that are dominated by two large pinacoid faces top and bottom and small prism faces forming a jutting angle on every side. There are many variations of these faces but the flattened blades and tabular crystals are the most common. If the pinacoid faces become diminished or are absent, the resulting prismatic crystal has a rhombic cross section.