Hi, all. I'm looking for black diamond necklace for my niece. She's turning 17 and she hinted that she wants something like that as a present. Not real diamonds though, my budget is around 100$, maybe a bit more if it's very nice. She's got good taste and she's quite mature, so I'm looking for something serious and at the same time eye catching.

I'm not finding a lot of things that I like though. Googling "black diamond necklace" I get either very expensive jewelry or it's not trendy or plain ugly. The choice is pretty bad. On etsy there are a few good ones, and prices are good.

Found some things I liked on pinterest. Right now I can't decide between a smooth glass-like jewel or unprocessed, jagged stone. I see both looking good on her.

Found this list on pinterest. I'm seriously considering #1 and #5. They're at the top of my list. #6 would be great, but it's a bit costly.
http://passantfox.com/post/bla.....5036015616

These are good price, and quite elegant I think
https://www.etsy.com/listing/1.....icate-gold
https://www.etsy.com/listing/2.....cklace-925

Expensive side, but love
https://www.etsy.com/listing/1.....roughrough
https://www.etsy.com/listing/2.....d-necklace

Gorgeous, but it's way too expensive
https://www.etsy.com/listing/1.....e-14-karat

What do you think? Any advice, or do you know vendors with stuff like this?

Thanks!