What is happening
Ultraviolet light excites electrons in trace activator elements, which release visible light as they return to their resting state. The activator is usually an impurity rather than part of the formula.
This is why fluorescence varies wildly between specimens of the same species from different localities.
Shortwave and longwave differ completely
Longwave lamps around 365 nanometres are cheap and common. Shortwave around 254 nanometres is more expensive and produces entirely different responses.
Many famous fluorescent specimens respond only to shortwave. A specimen that is dead under a longwave lamp has not been ruled out.
Shortwave needs eye protection
Shortwave ultraviolet damages eyes and skin. Use proper filtering goggles, keep exposure brief, and never point the lamp at anyone.
The cheap lamps sold without filters are the dangerous ones, because they emit visible light that makes the invisible hazard feel smaller than it is.