Mermaid's Pendant

Give this to the person you want to marry.
Overview
The Mermaid's Pendant is an item used to propose marriage to a marriage candidate. It is purchased from the Old Mariner for 5,000g. The Old Mariner appears on the beach, beyond the bridge that costs 300 wood to repair, and only visits on rainy days between 6:00 AM and 7:00 PM. He can also appear in Winter if a 
To buy a Mermaid's Pendant, the player must meet two requirements: reach 10 hearts of friendship with a marriage candidate, and have bought and completed the first farmhouse upgrade. Since 10 hearts requires giving the candidate a bouquet at 8 hearts, the pendant is effectively a late-step item in the marriage process. Once obtained, it can be given to any marriage candidate to propose. The item cannot be sold.
If the player is already married or has a housemate, the Old Mariner still appears but will not sell a Mermaid's Pendant. If the player divorces, a new pendant can be bought later and given to another marriage candidate. If the player is engaged but not yet married, another pendant can also be purchased from the Old Mariner.
A few interaction details are worth noting:
- The Old Mariner refers to the pendant as an "old amulet."
- Trying to give a Mermaid's Pendant to someone while already engaged triggers a refusal line instead of a proposal.
- Trying to give it to someone while already married also triggers a refusal line.
Because the Old Mariner only appears under specific weather and time conditions, players often wait for a rainy day before making the trip to the beach. Repairing the bridge is also necessary before he can be reached, so the pendant cannot be bought until the beach area has been expanded. In practice, the item serves as the final marriage token: once the friendship and house requirements are met, it becomes the only thing needed to turn a romantic relationship into an engagement.
Official description
Give this to the person you want to marry.