Signed Loose gemstone Gorgeous Opal Natural Doublet Freeform 5 carat app 12 mm triangle loose gem scrap gold jewelry cts October Birthstone

This opal is so pretty!

Details-
I have put off listing opals because I do not know them very well. I will list these to the best of my ability.
I do not know how to test opals and do not know where to send them for testing in an affordable way, so I will do my best to tell you what I think they are and will guarantee them as such. Also, opals are very difficult for me to photograph and the colors seem to look different in person than in the photos. It seems often, the reds seem to disappear and the blue tones seem more concentrated.
My opinion: Natural opal: Looks like a doublet. It is signed on the bottom. At first I thought the top was several pieces, but from the way the fire hits it, it seems to be one piece with different color tones. It is a really classy looking opal.
Measurements: 12.2mmx11.7mm , 3.9mm deep
Weight: 4.97 carats
Cut: Freeform triangular
Condition: Good.