Ice 9,
Sharp peaks at blue, green, Yellow, UV and plenty of IR, other wavelengths are nearly non existent. Coated mercury vapor lamps also have a moderate red peak due to the phosphor coating.
Coated (delux) mercury lamps are only slightly better overall than incandescents for growing. You can use them sucessfully to supliment HPS lamps but their efficiency is low.
A 400W Merc vapor only outputs 21K lumens. Compare that to 40K lumens for a 400W super halide and 50K lumens for a 400W HPS and you can see why their not often used for grow lights.
I used them once, years ago (My first HID
) but I haven't owned or used one since.
Hope this helps, Harrad.