Gems

Gems are rare resources that can be obtained randomly from Mining or by combining 10 gem fragments obtained from gathering. You will only start finding gems after finishing the The Gem Seeker quest, however, the Miner does not have to be mining for you to find gems. This means that unlike Ores and Geodes, running more Mining Machines or Miners will not increase your chance at finding gems. In fact, nothing in the game can boost your gem luck rate; it is purely luck.

There are four types of gems which can be found: Sapphire, Emerald, Ruby, Diamond.

Gem		Rate (Ticks)	Rate (Per Day)	Avg Gems / 100 Days	Sell to Game Shop
	Sapphire	1/100,000	1/1.16	86.40	10,000
	Emerald	1/250,000	1/2.89	34.56	25,000
	Ruby	1/500,000	1/5.79	17.28	50,000
	Diamond	1/1,000,000	1/11.57	8.64	100,000

Uses

Upgrading Tools

Gems can be used to upgrade all Tools, to provide increased rates, decreased Stardust costs (e.g., Pickaxe and Hammer), or otherwise enhanced effects for that tool. Gems must be "socketed" in a tool with the Socket Scroll in ascending order, from Sapphire to Emerald to Ruby to Diamond. Because they provide permanent buffs, it is generally advised to use all gems to upgrade your tools first, before using them for other purposes. It is generally advised to first upgrade your Brewing Kit, Axe, and Fishing Tools.

Treasure Chest Keys

Gems can be used to craft Treasure Chest Keys, which are used to obtain loot from Treasure Chests. Higher tier gems will provide more rolls on the loot table when opening the chest. Because of the relative rarity of obtaining Treasure Maps, it is generally advised to use at least an Emerald Key when opening chests, if not higher.

Gem Stardust Potions

The Stardust Potion, Great Stardust Potion, and Super Stardust Potion can be used to gain Stardust over time. The Stardust yielded is based off your Brewing level.

Selling

Gems can be sold either to the NPC Shop or the Player Market. Lower tier gems (Sapphires and Emeralds) generally only sell for slightly above the NPC Shop on the Player Market, but Rubies and Diamonds sell for significantly more on the Market.