Diamonds are the only resource that is account wide, so diamonds you earn in one of your cities can be used in any of your other cities. This is something you can take advantage of. Start a city in another world (or multiple) for the sole purpose of farming diamonds. Get as many wishing wells as you can from events, and fill up these “diamond farm” cities with them. Depending on how many wishing wells you have, you can actually make a lot of diamonds from this. WWs have a 1% chance at giving 50 diamonds, so for every 100 wishing wells you have, you will get on average 50 diamonds per day. This really can add up if you have multiple diamond farms, with lots of WWs in each.How can you collect more diamonds without having to purchase them