Actually, the the name is "MicroMagic" (I keep turning the name around, too :) )
Here's a clickable version of Nsgarch's link to the Swiss web site:
http://www.dietiker-humbel.ch/micromag.htm
And with English translation:
dietiker-humbel, as above
And link to a page with photos of the Magic Diamond cartridge:
Photos

http://www.6moons.com/audioreviews/walker4/headshell.jpg
.
Here's a clickable version of Nsgarch's link to the Swiss web site:
http://www.dietiker-humbel.ch/micromag.htm
And with English translation:
dietiker-humbel, as above
And link to a page with photos of the Magic Diamond cartridge:
Photos

http://www.6moons.com/audioreviews/walker4/headshell.jpg
.