Is this a good Diamond?

[NYCorBUST]

Sorry I am a Newbie.

Anyhow, I am going to ask my GF to marry me in two weeks or so. I looked at some diamonds and this GIA Cert is one that I "thought" looks good. What do you all think?
GIA
Shape and Cutting Style: Square Modified Brilliant
Measurments: 5.5x5.43x4.02 mm
Weight: 1.04 carat

Proportions
Depth: 74%
Table: 73%
Girdle: Medium to Thick
Culet: NONE

Finish
Polish: VERY GOOD
Symmetry: GOOD

Clarity Grade: SI2
Color Grade: J
Fluorescence: FAINT

Now I thinking about buying the Diamond Mentioned with this as a Gold band.

Should I do 14 Karat or 18 Karat - since there are only 4 prongs?
Do I have a Good Diamond?
Will The Gold Band make the J color look Great?
How is the Cut?
I am REALLY new to this so any info will be great!
The price is $4,100.00
-EDIT THIS IS THE COMPLETED COST OF THE TOTAL RING ALL TOGETHER.-

What do I need to look/ask for when buying?
I read do not use cash? That one should use credit?
Any buying tips?

Thanks,
JD

 

[NYCorBUST]

Oh sorry more questions...

Will this sparkle?
Where/what lighting may it look bad?
Is it worth the cash?

Sorry I just really have no clue, and I am searching the net, but I find a wide variet of differences!

THANK YOU ALL!!!!

 

[NYCorBUST]

Sorry if this is the "usual" newb questions.
I have just been doing this since 10pm and now I am looking for guidance.

 

[strmrdr]

Im not a square stone expert and but id pass on it.
Symmetry: GOOD bugs me because it often means the stone is poorly cut and leaks light.
If they didnt get that right the odds are they didnt get the rest right.

Someone better versed in them should be able to help you out further.
If I was into them id start with goodoldgold .com then whiteflash.com expert selection.
The will both have them in stock rather than being virtual stones and have more information available.

 

[pearcrazy]

I have to disagree with strmrdr that "good" symmetry means a poor cut. My diamond is rated good/good and it sparkles like crazy. My only hesitation would be the J color in a fancy shaped stone may show more yellow that it would in a round. Also, have you actually seen this SI2? They aren't always eye clean.

 

[NYCorBUST]

Yes I have seen this Si2, and I can''t see any flaws with the naked eye, I can see one in a microscope.

I also read that the color J would be less noticable in a Gold Band. Is this true?

 

[Hest88]

The table''s somewhat larger than I''d like, but it might be lovely. The problem is that without more stats it''s difficult to tell if it''s a good performer or not. However, if you''ve seen it and think it''s gorgeous than I''m sure she''ll love it.