And now the Solution
There's a lot of steps to solve this puzzle, and many ways to get to the answer. Here's one way.
The Clues:  Mr. Goldwater did not find coins.
 Hicks' treasure was worth $50 more than Dulcie's, and $50 less than Goldwater's.
 Iverson hunted earlier in the day than Hicks.
 The most valuable treasure was found on May Day.
 Only one detectorist hunted in the afternoon, and they found the earring.
 Candace hunted earlier in the day than Jones.
 The detectorist that found the cheapest treasure hunted only on the weekend.
 Of the two morning hunters, one had his second hunt on Tuesday, which yielded no treasure.
 Because of church, nobody hunted Sunday morning.
 Ms. Franklin was the only person to find a gold treasure, and Aaron was the only person who didn't find jewelry.
 Due to the Cinco de Mayo festivities, nobody hunted the evening of that day.
 Erin found her treasure on Monday, it was worth $100 more than the earring, and $50 less than Iverson's.
 Only two detectorists hunted in the evening.
 Candace originally intended to hunt on May Day, but she had to go to a one o'clock luncheon so she hunted the next day instead.
 The five detectorists were the lady that found the $100 treasure, the man that hunted on Monday Evening, Hicks, Aaron, and the detectorist that found the gold bracelet.
 Brian was particularly amused that he found the brooch on Star Wars Day.
The Steps:  S1. From #1: Goldwater is male, and therefore can only be Aaron or Brian.
 S2. From #2: Dulcie is not Hicks or Goldwater, that Dulcie's treasure can't be $250 or $300, that Hicks can't be $100 and that Goldwater can't be $100 or $150.
 S3. From #3: Iverson didn't hunt in the evening, and Hicks didn't hunt in the morning.
 S4. From #4: $300 treasure was found on Saturday, May 1 (May Day).
 S5. From S2 & S4: although Dulcie could have hunted Saturday (we don't know yet either way), she did not find her treasure that day.
 S6. From #6: Candace is not Jones, Candace did not hunt in the evening, and Jones did not hunt morning.
 S7. From #7 & #4: The $100 treasure was found on Sunday (it had to be a weekend day and the $300 treasure was found on Saturday.)
 S8. From S2 & S7: Since neither Goldwater nor Hicks found the $100 treasure, although they could have hunted Sunday, we know they did not find their treasure that day.
 S9. From #5 & #8: 2 hunted in the morning, 1 in the afternoon, and 2 in the evening. Also one of the men was a morning hunter, who hunted Tuesday and an earlier day, and found his treasure on that earlier day.
 S10. From #9 & S7: since nobody hunted Sunday morning, the $100 treasure was not found in the morning. Also there had to be a hunt Sunday afternoon and evening.
 S11. From #10: Franklin is female, and therefore must be Candace, Dulcie or Erin. Franklin found the gold bracelet (the only gold treasure). Aaron and Brian could not have found the gold bracelet. Aaron found the coin cache.
 S12. From #5 & S11: Since the earring was found in the afternoon, and only one detectorist hunted in the afternoon, the gold bracelet and the coin cache were not found in the afternoon, and therefore neither Franklin nor Aaron are afternoon hunters.
 S13. From #11: since nobody hunted Wednesday evening (May 5, Cinco de Mayo) then there had to be hunts in the morning and afternoon that day.
 S14. From S10 & S13 & #5: since each detectorist hunted two days, and only one detectorist hunted in the afternoon, and Sunday and Monday had afternoon hunts, then none of the other days had an afternoon hunt, so Sat, Mon, & Tue all had morning and evening hunts. Further, since the afternoon hunter found the earring, the earring could only have been found on Sunday or Wednesday.
 S15. From S4 & S14: since the $300 prize was found on Saturday, and the earring was not found on that day, the earring cannot be the $300 treasure, and the $300 treasure was not found in the afternoon.
 S16. From #12 & S3 & S15: Erin is not Iverson, Monday was one of her hunt days, she did not find the earring, her treasure was not $100, $150, or $300. Iverson did not find the earring, and Iverson's treasure cannot be $100, $150, or $200. The earring cannot be $200, $250, or $300 (because it is worth $150 less than Iverson's treasure). Also since the earring was found in the afternoon and neither Erin nor Iverson found it, neither Erin nor Iverson is the afternoon hunter. From S13 we know that Iverson also didn't hunt in the evening, which means Iverson must be a morning hunter.
 S17. From #14: Candace had to reschedule her hunt due to a 1 PM appointment. This means Candace is the afternoon hunter.
 S18. From #5 & S14 & S17: Candace found the platinum earring, and hunted Sunday and Wednesday.
 S19. From S15 & S18: since the earring cannot be the $300 treasure, and Candace found it, then Candace did not find the $300 treasure.
 S20. From S1 & S6 & S11 & S16 & S18: Since Candace is not Goldwater nor Jones, then neither Franklin nor Jones found the earring. We know (from S16) that Iverson didn't find the earring, and (from S11) neither did Franklin. That means only Hicks could have found the platinum earring, which means Hicks is Candace.
 S21. From S20 & S19 & S2: Candace Hicks didn't find the $100 or $300 treasure, and the earring is therefore neither $100 nor $300.
 S22. From S21 & S7 & S18 & S10: because the earring is not the $100 treasure, and the $100 treasure was found on Sunday, the earring was not found on Sunday. The only other day Candace hunted was Wednesday, so the earring was found Wednesday. Further, since the $100 treasure is not the earring it wasn't found in the afternoon, but from S10 we know it wasn't found in the morning. This means the $100 treasure had to be found in the evening.
 S23. From S6 & S17 & S20: from S6 we know Jones didn't hunt morning, and from S17 & S20 we know only Hicks hunted in the afternoon, which means Jones must have hunted in the evening.
 S24. From S16 & #9: Iverson did not hunt Sunday. Likewise from S23 & S13: Jones did not hunt Wednesday.
 S25. From #15: the person who found the $100 treasure was female, so it couldn't have been Aaron or Brian.
 S26. From S25 & S2 & S16: Aaron, Brian, Candace, and Erin did not find the $100 treasure, which means Dulcie did.
 S27. From S26 & S7: Since she found the cheapest treasure, Dulcie hunted Saturday and Sunday, and made the $100 find on Sunday.
 S28. From S27 & S22: Since the $100 treasure was found in the evening, Dulcie hunts in the evening.
 S29. From #15 & S26: Dulcie did not find the Gold Bracelet.
 S30. From #10 & S11 & S18 & S29: Aaron, Brian, Candace, and Dulcie did not find the gold bracelet, which leaves only Erin. Since (from S11) we know Franklin found the gold bracelet, then Erin is Franklin.
 S31. From S8 & S16 & S26 & S30: Since Erin is Franklin, we know that Franklin's treasure could not be $100. From S8 we know that neither Goldwater nor Hicks finds could be worth $100, and from S16 we know Iverson did not find the $100 treasure. That leaves only Jones as the finder of the $100 treasure. From S26 we know that Dulcie found the $100 treasure, which means Dulcie is Jones.
 S32. From S11 & S31 & S18 & S20 & #1: we know Dulcie did not find the coin cache, and Dulcie is Jones so Jones did not find the coin cache. From S18 & S20 we know Candace Hicks did not find the coin cache. From S11 we know Erin Franklin did not find the coin cache. From #1 we know that Goldwater did not find the coin cache. Having ruled out Franklin, Goldwater, Hicks, and Jones, only Iverson is left. Iverson found the coin cache, and since we know from S11 that Aaron found the coin cache that means Aaron is Iverson.
 S33. From S30 & S20 & S31 & S32: we know Erin is Franklin, Candace is Hicks, Dulcie is Jones, and Aaron is Iverson. That leaves only Brian and Goldwater, so Brian is Goldwater. We now know the full name of each detectorist.
 S34. From S2 & S33 & S16 & S26 & S18: Since Brian is Goldwater, and Goldwater's treasure is not $150 (from S2), then neither is Brian's. From S16 we know neither Aaron Iverson's nor Erin Franklin's treasure is $150. From S26 we know Dulcie Jones' find is not $150. That leaves only Candace Hicks as the $150 treasure finder, and since she found the earring (from S18) the earring is worth $150.
 S35. From #2 & S35: Hicks' find is worth $50 less than Goldwater's. Since we now know Candace Hicks' find was worth $150, Brian Goldwater's must be worth $200.
 S36. From #12 & S11 & S34: Erin's find is worth $100 more than the earring, which we know to be $150, so Erin Franklin's find (the gold bracelet) was worth $250. And since Erin's find is worth $50 less than Aaron Iverson, then Iverson's treasure must be worth $300. We now know the value of each detectorist's find.
 S37. From #5 & #12 & #15 & S17: we know that Aaron Iverson did not hunt Monday Evening but that a man did, and that Erin hunted Monday. There are only two men, and since Aaron didn't hunt Monday evening, Brian must have. Since Candace is the only afternoon hunter, then the only time Erin could have hunted Monday was the morning. We now know what time of day everyone hunted.
 S38. From #4 & S11 & S36: we know the most valuable treasure was found Saturday, that Aaron found the $300 (most valuable) treasure, and that Aaron found the coin cache. Therefore Aaron hunted on Saturday and found the coin cache that day.
 S39. From S38 & S27 & #12 & S36 & S22 & S34 & S35 & S37: we know Aaron found the $300 treasure on Saturday, Dulcie the $100 treasure on Sunday, Erin the $250 treasure on Monday, Candace the $150 find on Wednesday. That leaves only Tuesday and the $200 find unmatched. So the $200 find was found on Tuesday. We know Brian found it, so in addition to hunting Monday Evening, Brian hunted Tuesday Evening. We now know what day each treasure value is matched with.
 S40. From #16: we know Brian found the brooch on May 4th, Tuesday. We had already worked out the day in S39, but now we know what treasure Brian found and that it was worth $200.
 S41. From S11 & S18 & S40: we know Erin found the bracelet, we know Aaron found the coin cache, we know Candace found the earring, and Brian found the brooch, that means Dulcie had to be the person who found the silver cross pendant. We now know who found each treasure, and on what day.
 S42. From #8 & S16: The only thing we have not yet identified is the day Aaron and Erin each had their second hunt. From all the previous reasoning, we know the only two remaining days which have an unidentified hunt are Tuesday and Wednesday. From #8 we know that of the two morning hunters one had his second hunt on Tuesday. We know Aaron is a morning hunter from S16, and he is the now only man who's second hunt has not been pinned down. Therefore Aaron's second hunt was on Tuesday, leaving only Wednesday for Erin's second hunt. And with that, we have solved the puzzle.
The Solution:  Aaron Iverson, morning hunter, found $300 coin cache Saturday, also hunted Tuesday
 Brian Goldwater, evening hunter, found $200 ivory & silver brooch on Tuesday, also hunted Monday
 Candace Hicks, afternoon hunter, found $150 platinum earring on Wednesday, also hunted Sunday
 Dulcie Jones, evening hunter, found $100 silver cross pendant on Sunday, also hunted Saturday
 Erin Franklin, morning hunter, found $250 gold bracelet on Monday, also hunted Wednesday
Thanks to everyone who gave this puzzle a whirl.
__________________
PlasteredDragon A.K.A. Chuck Seggelin
2 x Garrett AT Pro  Garrett Pro Pointer  18" Sampson Lesche  407 HUNTS
Clad: $636.43, Ag: 90%=$4.75, Oldest: 1835 1/3 Farthing
Au: 22k=6.9g, Au: 14k=13.59g, Rings: 31 (2 Au, 8 Ag, 21 junk)
