Dual Shortwave and Longwave Ultraviolet UV lamp. The most popular use of our lamp is for finding and viewing fluorescent rocks and minerals. Fluorescent rocks can be found all over the world and are found at many rock shows throughout the world. Fluorescent minerals respond best in dark conditions and most need a filtered shortwave lamp with optical filter. The optical filter blocks out any unwanted visible light generated by the led which generates unwanted visible light and can mask the fluroescent color response. 90 percent of fluorescent minerals need shortwave UV which is key for collecting fluorescent rocks. 3*255nm leds for shortwave UV and 3^365nm for longwave UV.