Gems

Gems are valuable crafting materials found underground. There are currently 7 Gem types. Gems can also be placed on any side of a block after being mined. They are found in any Underground layer, except for the Underworld.

With the exception of Amber (which requires an Extractinator instead), Gems are found in the following forms, all of which drop Gem items when mined:
 * Embedded within Stone blocks.
 * In placed form on blocks underground, including sometimes in Underground Cabins, or rarely in the Dungeon.
 * As gem stashes, which are breakable background objects (similar to Coin Stashes), each resembling a rock with gems protruding.

Gems can also be found in higher concentrations in rare Gemstone Caves, which can contain multiple Gem types lining and embedded within their stone blocks.

Types
In descending order of rarity and value (rarest at the top):

Uses
Gems can be sold to NPCs as a good pre-Hardmode source of coins. Additionally:

All gems:
 * can craft Gemspark Blocks of a corresponding color.
 * can be combined with torches to create colored torches.
 * can be crafted into gem staffs (magic weapon).
 * can be crafted into Large Gems for the PvP game Capture the Gem.
 * can be crafted into Gem Locks, containers or altars for Large Gems.

All gems except Amber:
 * may be crafted into a colored Hook at an Anvil.
 * can craft a Phaseblade of matching color. Every color has identical attributes.
 * can be imbued into Robes.

All gems except Amber or Diamond:
 * can craft Stained Glass.

Other recipes:
 * Topaz can be used to craft the Sandgun.
 * Rubies can be used for the crafting of the Gold Crown and Platinum Crown.
 * Amber can be used to craft Crate Potions.

Gemstone cave


A Gemstone cave is a rare, irregularly shaped room often found in the Cavern layer. They contain a high concentration of placed gems on multiple stone surfaces, as well as a few gems embedded in stone. Most gemstone caves contain one or two types of gemstone, but can rarely contain three or more types. The type of gem found in such caves is easily identifiable by the Gem Wall the cave utilizes, but this wall cannot be collected to obtain any items.

History
宝石 Gemmes 보석 Gem Gem Драгоценные камни