This is a problem with the Nautilus Mini, but
@Cosmic_Glaze has it exactly right: it does not need to be tightened down. If you look at how it actually comes together, it's the coil head that is screwing into the chimney section (not the glass part screwing down onto the base) that holds it together.
Once the coil head is gently screwed in, it doesn't need any more tightening, and will be very difficult to unscrew if overtightened. That big ol' clear "o ring" part at the bottom keeps it from leaking, but you do not need to screw the glass down tight to ensure that. Once I realized this I haven't had any problems with mine!
For now, try holding both the glass and the base with rubber kitchen gloves and persistently turn the base clockwise, and the glass anti-clockwise. Good Luck!