Yep you guessed it Steven Quartz/Diamond
Universe

WOW 0.0  I love his diamond form it looks
Awesomeee!!!

I love the design the background is more reddish than pink but ehh I think it looks good either way and I love Stevens character  design it looks fabulous and
I love the little diamond sparkles in the background  and his character design is just so cool I mean look at this are boy finally
Has a neck XD 

Anyway moving on...

WOW O_O  so ruggedly handsome  Steven
Is dressing to impress I must say this boy has some good taste in fashion and on his
Vest/ tuxedo the diamond insignia looks
Marvelous and at the top it is pinned by a rose I really like his character design 
It looks stunning and he looks a little older
And more matured  and again he has a neck
XD

I love this one and it is very similar to
The last one the difference is he looks younger here

WOW o_O  I love it the only thing is that it doesn't have any color but that's okay
I love his shoulder pad and cape and glove
I like everything about his character design

WOW  also I love the side burns and he has
A NECK X"D someone please help me...

I love his long hair  and his muscles
But most importantly the shield that is so cool it is LITERALLY  shaped like a diamond
His character design is excellent

WWowww o.O 

Poor Steven it really is difficult  and it must be hard having to deal with the pressure of
Being a diamond and countless of other stuff  that can really effect him mentally and emotionally

Cool boots and I love the cape...

Amazing...

Love it...