Out of all the gems that Link has a chance of finding in Tears of the Kingdom, diamonds are among the best and they can be a fantastic way to earn some extra Rupees. However, rare gems are difficult to find and largely up to chance within TotK, but we can make the best of the situation, and I even know of a place that sells diamonds at a pretty steep price.
Where to Find Diamonds in Tears of the Kingdom
One place where you can guarantee diamonds is Goron City at the gem shop. The coordinates for Goron City are (1646, 2444, 0382). Considering the area is known for mining, it’s not a surprise that the Gorons have a shop dedicated to Diamonds, and they can be purchased for 1,000 Rupees at the display like you can with other shops in the game. However, that’s a high price for gems and may not be worth the trouble.
You can find diamonds out in the wilds of Hyrule as you explore the map, but you need to look for cave entrances or mines. When you enter these areas, there are ore deposits, which you have likely run into before. There are blue deposits and gold deposits that indicate the possible rarity of the ores within. Gold deposits are the ones that diamonds can drop from in Tears of the Kingdom.
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With a blunt object like a rock hammer, I have destroyed plenty of the gold deposits to earn rare gems on the ground such as a Ruby or Topaz. The only problem is the reliance on chance when it comes to getting diamonds in the wild. You can only hope that one of the expensive gems pops out of a deposit in TotK.