Gem bag

The gem bag requires level 25 Crafting and Dungeoneering, as well as 2000 Dungeoneering tokens (making it the least expensive non-experience reward). It can hold up to 60 uncut gems (and only in their uncut state) of the following gem types:
 * Uncut sapphire
 * Uncut emerald
 * Uncut ruby
 * Uncut diamond
 * Uncut Dragonstone

To deposit a gem, just use it with the gem bag or left-click the bag to store any uncut gems in your inventory. You will get the message: "You add the gem[s] to your bag." The gem bag has the following options:
 * Fill
 * Withdraw
 * Inspect
 * Your gem bag has # sapphires, # emeralds, # rubies and # diamonds.
 * Use
 * Empty
 * Destroy
 * Gems inside
 * You can't destroy this item with gems in it.
 * Examine

Uses
The Gem bag can be used to save inventory space when mining gem rocks in locations such as the Shilo Village mining site, the Lunar Isle mine, and the Al Kharid mining site resource dungeon (level 75 in Dungeoneering required). The bag can also save inventory space when collecting gems dropped by goraks and abyssal demons, who drop gems frequently. Additionally, it can be used to store gems gathered when mining regular rocks, cracking a wall safe in the Rogues Den, training Slayer, and so forth.

The gem Bag is also useful when crafting items such as rings, necklaces, bracelets or amulets with a gem. You can have the gem bag and a number of gold ores/bars in your inventory (saving at least 1-2 space for gems to be withdrawn). Walk to a furnace, withdraw a gem, cut it with your chisel (since the gem bag does not store already cut gems), craft it with the gold bar, withdraw another gem, and repeat.

The gem bag can also be used while doing muddy key runs into the wilderness. The muddy chest yields one uncut ruby every time it is opened. Therefore the gem bag can allow a player to carry back much more loot from the chest.

Finally, storing gems in the bag saves bank space. This is particularly useful for free players as they can save up to three spaces if they had all gem types in their bank. Players may only own one gem bag at a time.

It should be noted that the gem bag stores 100 gems in total, not 100 gems of each type. It should also be noted that if you die, the gem bag is completely lost, along with any gems inside. This item will not appear under your gravestone, nor will any gems it contained.

Trivia

 * The maximum coin value that can be stored in a Gem Bag is coins, the combined cost of 100 uncut dragonstones.
 * The gem bag used to cost 13,000 Dungeoneering Tokens before the 21 April 2010 update.
 * The gem bag used to only be able to hold 40 gems and was unable to hold uncut dragonstone gems before the 27 May 2014 update.

Gem bag Gem bag