EDIT HE IS NOT a fusion. I'll be honest I have just started watching SU and didn't know about it's only in ONE place I saw Garnet having 2 in her hand but i was informed thats because of "reasons" (spoilers) so my reason behind him having multiple gems, is he's so fragile, in his younger years his main gem had broken two small pieces off. He freaked out and grabbed them with his hands to put them back into the cracked spots and thats when the two pieces stayed in his hands. (THATS MY STORY AND IM STICKING TO IT)

Ok I blame the SHIT out of the wife for this.
She got me to watch SU and I broke and made a Gemsona today.

YES male because I am male. (it's P much me as a gem ok)

So here we have HEMATITE
a very shy and fragile gem he has NO confidence in himself what so ever and you can see him mostly sighing and being depressed because he thinks he's useless. (YEP THATS ME)
He's very Femme and is constantly being called a female (IRL happens to me all the damn time but I'm also femme boy)
Hematite is a magnetic gem. instead of walking since he's weak and fragile. He floats using the Earths core (like Magneto)
His Gem is in his back (which he tries to cover up with the cloak) and two smaller ones IN his hands.
His weapon is this boomerang scythe (also makes the letter "H" hurr) that he controls with the gems on his hands via magnetic pull etc.
It's like he conducts waving his hands like music conductor BUT (just like me IRL) He forgets his left from his right so sometimes that blade is ALL over the place.

IF he were in the actual show.
Amethyst would pick on him, giving him punchies and since he's so fragile he'd get broken arms. He would probably be a gem most times. poor baby.
Pearl would "appreciate" his help but she'd be more concerned and try to protect him (like Steven)
Steve would be amazed since Hem is a male gem. and they would be bros. but Hem would still be super shy.
Not sure on Garnet yet.

Also he will have a corrupted gem side and a fusion.

Gems © Steven Universe
Hematite (Hem) and art © me

ALSO I have found only TWO Hematite gemsonas but they are female
http://www.furaffinity.net/view/16248124/
http://www.furaffinity.net/view/15990890/