Thank you for using Just Answer. Assuming you live in Florida and the sale was made in Florida:
We need to know what kind of tax you're talking about.
For sales tax, we'd need to know in what (county) you make the sale.
For income tax, we'd need to know how long you've held the jewelery, how much you paid for it, and information about your other income and deductions.
I'm sorry about the confusion. The above was not intended as an answer, but as a request for information. I had a computer glitch. Please do not feel obligated to "accept" the answer, as it's not yet complete.
Assuming you live in Florida and the sale was made in Florida:
It's not entirely obvious, but there doesn't appear to be a sales tax consequence, although the purchaser may need to pay New Jersey use tax. That's not your concern, however.
If the the jewelry was a gift, then I'm afraid you need to know the basis it had in the hands of the giver, in order to determine whether any Federal capital gains tax is due.
Your basis for calculating a gain is the giver's basis, unless he or she paid gift tax. Gain is taxable as a long-term capital gain as a "collectible" item, so (after being offset by any capital losses, which you may very well have if you have investments), it is taxed at your regular tax rate, but limited to 28%.
Your basis for calculating a potential loss is the lesser of the giver's basis and the value of the jeweler at the time of the gift, although, if you used the item of jewelery, losses are not deductible.
I'm afraid I made a mistake above, but thank you for clarifying and giving me an opportunity to correct my mistake. It now appears that this was not a "gift" under IRS definitions, as you got it in return for some sports activity.
If, hypothetically, you are http://en.wikipedia.org/wiki/Tom_Nieto , then of the New York Yankees, the ALCS championship ring should have been reported as part of your salary in 2001. It's still a collectible, but your basis is what was then reported.
I'm afraid it's too late for it to be considered "confidential", as anyone who happens to be reading the tax section can see this, but it will disappear from there within 24 hours. I won't reveal it to anyone, though.
May I suggest that you close the question as soon as you receive an answer you can accept, to reduce the time it is visible to other people. I have no idea whether this site is indexed by Google, but if it isn't, there will be little trace of your question and answer after the question is closed.