Example, i have a ring that have a little blue circle ,and it Absorb Fatique 40 pts on Strike, when i wear it, it came from a Oblivion Gate,i made it my selv, i think Sirgil Stone?

I want that to move that to a knife, can i that ? ,or will it forever be what i first take?

Thanks

Enchantments can't be moved after they're made, but you can keep finding more enchantable items, and there will be more Sigil Stones available, until the Main Quest is completed. The strength of the Sigil Stone enchantments gets higher as your character level increases, so it's common to sell the first things you use them for, once you get better ones.

Thanks, i will do that, i found a better weapon, and will use Sirgil stone for that, but i must go for a new one then.(Sirgil Stone)

By the way, can i get a Sirgil Stone, i Obvilion Gate, when i not do it in a Quest?

just go there when i see one?

you just go in a gate when you see one and close it by taking the sigil stone. in total there are 60 gates you can close and they are can be placed in 90 different locations, (or atleast it think.) two gates are fixed, the kvatch gate and the great gate. maybe the gates you got to close in aid for bruma are on a fixed location too, i'm not sure about that.

It sounds like the stone you put in a ring is one you got between character levels 13-16 (Ascendent Sigil Stone). The most powerful ones become available at level 17. Sigils have two capabilities, depending on whether you stick them in a piece of apparerl (like a ring) or a weapon. 40 points of aborb fatigue is the weapon effect; I suspect your ring bears its other ability: Fortify fatigue 40 points.

When you grab a sigil stone, its nature is determined then. Therefore, you may wish to save the game, grab the stone and check it out. If happy, keep it. If unhappy, reload your save and try again.

More info on them here: http://www.uesp.net/wiki/Oblivion:Sigil_Stone

After you use a stone to enchant an item, it's gone for good. You cannot re enchant or remove enchantments. I'd recommend saving before enchanting rare items if you can help it.

If you'd like to experiment the possible outcomes, save right before you pick up the stone.
Your level tier determines the strength of the stone. Between levels 1-4 you will always get a Descendant Sigil Stone. 5-8 Subjacent, 9-12 Latent, 13-15 Ascendant, and 17+ a Transcendent Sigil Stone. I don't know the specific numbers based off of the tier or every possible enemy and character effects, so I'll leave that discovery to you.

I'd recommend going through the main quest because it requires you to go through every gate type anyway. A good place to stop is right after closing the great gate. Once you finish the main quest your chances to experiment are over. I believe I was able to easily give myself 100% chameleon using 3 sigil stones and an artifact.

EDIT-Accurate info.

One more thing is worth mentioning. A lot of players will close the Kvatch gate and save the city at an early level, when it's easy, and then drop the main quest until later.

If you do that you get just the one sigil stone. It happens that there are two magic effects from sigil stones that are the same at any level: Water Walking and Nighteye. So, if you want to make the best possible use of your one low-level sigil stone, you could consider saving before grabbing the stone, and reloading until you get one of those two effects. I find that constant-effect Water Walking enchanted on a pair of shoes is a powerful advantage for a low-level mage.