I got a 286 ctw. Amethyst 42mm by 33.50mm, weight 57 grams. Ihave attach a pic, how much will that go for?

I have an amethyst ring recently appraised, four amethysts and rubies, and I just had it appraised for $350. The gold in the ring is worth a lot more, quite naturally.

If you want an accurate appraisal, go to a jewellery store and have it done properly and at the same time you will have the paperwork that certifies the appraisal if you want to sell it.