WELLDONE present Creative Stylish Desktop Drops Storm Glass Crafts Weather bottle Forecast Bottle Barometer(Mini) The appearance of the liquid transforming from clear to cloudy to crystal flakes predict whether the weather will be clear, cloudy, or filled with thunderstorms. Unique and unusual gift:The cool new and modern Storm Glass is a natural way to forecast the weather. While it can't ever be as accurate or reliable as a barometer or actual meteorological forecast, the patterns made are gorgeous and makes for a stunning decoration on any desk and dining table. Out of the box there are crystals in the lower quarter and it will be interesting to see it come to equilibrium and then react to weather Note : the Storm Glass may need one or two weeks for the crystal to stabilize and adapt to the environment. If you want to see the test result, can be placed in the refrigerator frozen half an hour to an hour, take a look at the change effect