Stupid noob question - levelling up skill gems

Apologies if this has been answered elsewhere, but I've just spent over 30 minutes searching the forum, the game and the interweb, and I can't find the answer anywhere.

HOW do I level up a skill gem? I have my first, and I've got the message that it is ready to level up. When I unsocket it, there is a little cross in the corner of the icon. I've clicked it, right clicked it, centre clicked, double clicked, watched the skills video, searched everything and the nearest anything gets is saying something like 'When you level up your gems...'

Starting to get a bit frustrated, this should really be in the faq somewhere!

Thanks for any help

Insert the skill in your gear then look at the bottom left corner of your inventory screen.

Right. When you have the gem socketed in your gear, a little icon will show up beneath your inventory with a '+' button. Press the button to level up your gem.

So gem lvl is like the gear lvl of that item

"

Nickfish wrote:

So gem lvl is like the gear lvl of that item

no, gem lvl is the level of the gem.

If you have say, Sweep at lvl 5, and get a new mace, just remove sweep from your current weapon, and put it in the new weapon and keep enjoying your level 5 sweep. :)

Thanks for the assistance! I suspected it would be something obvious, which is why I got annoyed with myself when I couldn't find it.