Chinese Hallmark On 18K Gold Pendant (Makers Mark?)

[Just Checking]

Hello, I purchased this pendant a few weeks back and have been trying to find out what the writing on the back which I believe is Chinese says. It is on the back of a 18 Karat gold Koi pendant.

I have tried to use the draw your character line dictionary at http://ce.linedict.com/dict.html#/cnen/ and the only character I am able to make out with a fair amount of certainty is the second one which I believe is "大"  "Da" Or "dai" from the website mentioned they are saying it means Big, great, Important. I know that the bottom part of the hallmark looks to be filled in on the first character and most of the last character is also filled in on the top which makes it very difficult to see. I am attaching 3 images, 2 are of the back hallmark and the other is of the front.

Thank you very much for your time!

[Tiana]

The other character is 福, which means "blessing".

[Lu]

I'd translate 福 as 'happiness', but it's the same idea. So 大福 'great happiness'.

 

It's a nice pendant!