Transparent crystal effect?

Ok, I'm pretty much goofing off at this point, and have concocted a modification of a starfighter with a phasor (a laser amplified by a refined crystal), and I'm trying to give it a colorful effect.

The outer shell is a semi-transparent cone with a jet black color, along with another semi-transparent cone with a dark purple shine... a Dark-Energy Phasor, if you will. But I am having problems with trying to make the dark purple cone visible, because the moment it submerges into the larger Black cone, it tends to disappear completely. I've tried resizing the cones to compensate, and even though it's helped, half of the crystal is still not appearing (it's two cones each, backs against one another).

These sort of slight little annoyances are usually the harder problems to solve sometimes, but I'm hoping anybody will have some ideas as to how to rectify the problem (namely Dr. Jim.... he's omniscient! ).

Any help on this problem is greatly appreciated!

Edit: For those of you who still use Cathode Ray monitors, you may have to boost your monitor's brightness a little...