Help needed to spot a synthetic sapphire. If it has color banding does it mean it is natural?

[nutellakitty]

Hello Everyone,

I got this piece from an auction site 3 weeks ago. I thought the package was lost during transportation because Fedex showed it was delivered to a different state!
However, 3 weeks later the package showed up outside my door. Haha.
I bought this ring for its design and it is in 18K YG(8g of gold,a very heavy piece).
The stone was described as "sapphire", the auction site did not say it was natural or synthetic.

When I opened the box, I thought it was synthetic. I have multiple natural sapphire rings, and this stone looks a little bit different from all the pieces I have.
Natural sapphires I own all have a very suble hue and color. This piece looks very transparent(not enough fire), and it does not have cratches or dent at all.
However when I looked at it under the loupe, I found the color band. Under UV light,this piece shows a strong fluorecent.
Now I am very confused. This piece is not that perfect to be a synthetic stone, not big enough in size, not in good cutting, and the color is not perfect.
Is that possible this piece is a natural purple sapphire?

 

[nutellakitty]

 

[Bron357]

Lovely ring.
Yes, that will be a natural sapphire. The colour zoning like that can’t be replicated in lab grown material.
And FYI Purple and pink sapphires, natural and synthetic will be fluorescent under UV light.