What a wonderful piece of family history you have. A presentation fob like this is much more than its gold weight.
The inscription you describe, presented to Capt. C. D. Robertson by the passengers, 22nd June 1844, and HARKAWAY on the other side, tells us this was a gift from the passengers of the steamboat Harkaway to their captain. Presentation pieces like this were given as a thank you for a safe passage, or for good service. They were treasured, and they were often kept in the family.
There was a steamer Harkaway working the western rivers in 1844, so your date fits the period very well.
I cannot give you an exact value from a description alone, and I would not want to guess. To value it properly, we would need to know:
1. The weight in grams 2. The gold purity, if it is marked, or tested 3. The size, and a clear photo of both sides 4. Any maker's mark or gold mark on the edge or ring 5. The condition, and if the original chain or fob fitting is still with it
The value will be in two parts. First, the gold value, based on weight and purity. Second, and often much more important for a piece like this, the historical and presentation value. A dated, named captain and named boat, with a passenger presentation, will interest steamboat collectors and river historians, not just gold buyers.
My advice is to please keep it safe, do not clean it harshly, and do not have it melted. If you can, have it weighed and tested by a reputable jeweller or appraiser, and keep a written note of your family history with it. That family story is part of its value.
Thank you again for sharing such an interesting piece.
