Just Pinned to Products I Love: At first glance, this might look like your average glassware, but set it in sunlight and you’ll reveal something special. Its 45 degree sloping bottom divides the glass in two triangular sections. When the glass cup is filled with water, the top section becomes a water prism that allows passing sunlight to project a rainbow on whatever surface it rests on. http://bit.ly/2qTrcnu
