In my opinion, it takes more skill to detect small pieces of gold jewelry at the beach, than large gold bands etc.
Never underestimate the value of being able to detect small pieces of gold jewelry, especially if you struggle to detect diamond rings.
Anyone can detect a chunky gold ring, but it takes a good search technique and a fine tuned metal detector to detect an expensive diamond engagement ring.
It takes even more skill to detect a diamond stud ear ring, imagine how many diamond ear rings are lost at the beach and go undetected.
Diamond stud ear rings and gold chains without pendants are some of the most difficult targets to detect at the beach.
Last year I recovered three half carat diamond stud ear rings and four thin gold chains without pendants, one of the diamond stud ear rings and two of the gold chains were recovered in the water.
The small pieces of gold jewelry were a pain to scoop, but well worth the struggle.
Many expensive diamond engagement rings, have large center stones mounted on relatively thin platinum or gold bands.
The band the large rock is mounted on is usually not very wide, making the piece of platinum or gold difficult detect if you do not use a sensible sweep speed and have a level search coil close to the sand.
Your equipment choices also have a lot to do with the size of gold you are able to detect at the beach, especially the size of your search coil.
Small search coils used correctly, are excellent at detecting small gold hidden in trashy areas.
If you use a very large search coil, your chances of recovering small gold diminish, especially at tourist beaches.
To answer Robs question, I search for small gold because it is often more expensive jewelry and because I never have a problem detecting small pieces of gold at the beach.