For the material, see gemstone.

Gems are simple, (usually) lightweight items you find in the dungeon. They come in three varieties: valuable gems, worthless glass which looks similar, and gray stones. Another type of item that uses the same glyph is the rock, which is dealt with differently.

Valuable (identified) gems may be sold for relatively large amounts of money at most general stores, which makes them valuable as a compact form of money. However, shopkeepers will always buy unidentified gems as if they are worthless glass, and will always sell unidentified gems as if they are valuable. (Gems are subject to the random +33% surcharge in recent versions.) Valuable gems may also be thrown to a co-aligned unicorn in order to get a large Luck increase. Throwing any valuable or worthless gem to a unicorn will pacify them, and will variably raise or lower luck in certain cases. See the unicorn page for more details.

More commonly, since money and Luck are overabundant later in the game, players save all of the valuable gems they find, stashing them away so that they can be added to the player's score upon the completion of the game. Glass and rocks are relatively worthless, though they can be used for throwing if you should wish to conserve your other attacks. Additionally, they can occasionally be polymorphed into more valuable gems if included in a polypile, though it's not worth wasting a wand charge on them. Rocks can also be changed in to meatballs, useful for taming and for sale in shops.

Despite the name, a worthless piece of <color> glass will not shatter like other glass items if thrown against a wall or dropped while levitating.

Gray stones are a catchall for four different objects until they are identified.

  • Touchstones may be used to identify glass from gems, and even the variety of gem if it is a blessed touchstone.
  • Luckstones will augment your luck rather impressively; if you have a blessed luckstone and no other luckitems, your good Luck will not timeout, bad Luck will, and you'll get +3 extra Luck.
  • Loadstones are a pun (dating back to early editions of Dungeons and Dragons): at 500 weight units, they weigh 50 times as much as the other gray stones, and they autocurse (and are generated cursed) so they cannot be dropped.
  • Flint stones have no particular purpose, but they do slightly better as sling ammo.

Tables of gems[]

By value[]

Some gems' appearances can change. In these cases all the options are listed. The actual appearance is randomly chosen from the options at the beginning of each new game. The hardness of a gem can be tested by #engraving with it; if the gem is hard, the game will prompt "What do you want to engrave?"; if it is soft, "What do you want to write in the dust?"

* Name Description Cost (zm) Weight Hardness Material
*White gem.png dilithium crystal white gem 4500 1 soft gemstone
*White gem.png diamond white gem 4000 1 HARD gemstone
*Red gem.png ruby red gem 3500 1 HARD gemstone
*Orange gem.png jacinth stone orange gem 3250 1 HARD gemstone
*Blue gem.png sapphire blue gem 3000 1 HARD gemstone
*Black gem.png black opal black gem 2500 1 HARD gemstone
*Green gem.png emerald green gem 2500 1 HARD gemstone
Green gem.pngBlue gem.png
turquoise stone green gem
blue gem
2000 1 soft gemstone
*Yellow gem.png citrine stone yellow gem 1500 1 soft gemstone
Green gem.pngBlue gem.png
aquamarine stone green gem
blue gem
1500 1 HARD gemstone
*Yellowish brown gem.png amber stone yellowish brown gem 1000 1 soft gemstone
*Yellowish brown gem.png topaz stone yellowish brown gem 900 1 HARD gemstone
*Black gem.png jet stone black gem 850 1 soft gemstone
*White gem.png opal white gem 800 1 soft gemstone
*Yellow gem.png chrysoberyl stone yellow gem 700 1 soft gemstone
*Red gem.png garnet stone red gem 700 1 soft gemstone
*Violet gem.png amethyst stone violet gem 600 1 soft gemstone
*Red gem.png jasper stone red gem 500 1 soft gemstone
Green gem.pngBlue gem.png
White gem.pngViolet gem.png
fluorite stone green gem
blue gem
white gem
violet gem
400 1 soft gemstone
*Green gem.png jade stone green gem 300 1 soft gemstone
*Black gem.png obsidian stone black gem 200 1 soft gemstone
*Orange gem.png agate stone orange gem 200 1 soft gemstone
*White gem.png worthless piece of white glass white gem 0 1 soft glass
*Blue gem.png worthless piece of blue glass blue gem 0 1 soft glass
*Red gem.png worthless piece of red glass red gem 0 1 soft glass
*Yellowish brown gem.png worthless piece of yellowish brown glass yellowish brown gem 0 1 soft glass
*Orange gem.png worthless piece of orange glass orange gem 0 1 soft glass
*Yellow gem.png worthless piece of yellow glass yellow gem 0 1 soft glass
*Black gem.png worthless piece of black glass black gem 0 1 soft glass
*Green gem.png worthless piece of green glass green gem 0 1 soft glass
*Violet gem.png worthless piece of violet glass violet gem 0 1 soft glass
*Gray stone.png luckstone gray stone 60 10 soft mineral
*Gray stone.png loadstone gray stone 1 500 soft mineral
*Gray stone.png touchstone gray stone 45 10 soft mineral
*Gray stone.png flint stone gray stone 1 10 soft mineral
*Rock.png rock rock 0 10 soft mineral

By color[]

The gems that have a randomized appearance are marked with an asterisk, "*".

Color Possibilites Cost Unidentified Sell Price Hardness
0 1 2
*White gem.pngWhite dilithium crystal 4500 4 4 6 soft
diamond 4000 5 5 3 HARD
opal 800 5 7 3 soft
fluorite stone* 400 4 7 4 soft
worthless glass 0 8 6 4 soft
*Blue gem.pngBlue sapphire 3000 8 3 6 HARD
turquoise stone* 2000 5 6 5 soft
aquamarine stone* 1500 7 3 3 HARD
fluorite stone* 400 4 7 4 soft
worthless glass 0 3 7 5 soft
*Red gem.pngRed ruby 3500 6 6 4 HARD
garnet stone 700 7 4 5 soft
jasper stone 500 3 6 3 soft
worthless glass 0 4 3 6 soft
*Yellowish brown gem.pngYellowish brown amber stone 1000 8 4 4 soft
topaz stone 900 3 5 5 HARD
worthless glass 0 5 4 3 soft
*Orange gem.pngOrange jacinth stone 3250 7 7 5 HARD
agate stone 200 6 4 6 soft
worthless glass 0 6 5 4 soft
*Yellow gem.pngYellow citrine stone 1500 6 7 6 soft
chrysoberyl stone 700 6 3 4 soft
worthless glass 0 7 6 5 soft
*Black gem.pngBlack black opal 2500 3 4 3 HARD
jet stone 850 4 6 6 soft
obsidian stone 200 5 3 5 soft
worthless glass 0 8 7 6 soft
*Green gem.pngGreen emerald 2500 4 5 4 HARD
aquamarine stone* 1500 7 3 3 HARD
jade stone 300 7 5 3 soft
fluorite stone* 400 4 7 4 soft
turquoise stone* 2000 5 6 5 soft
worthless glass 0 3 3 3 soft
*Violet gem.pngViolet amethyst stone 600 8 5 6 soft
fluorite stone* 400 4 7 4 soft
worthless glass 0 4 4 4 soft


Twelve guaranteed real gems can be found in the corner turrets of Fort Ludios: three diamonds, three emeralds, three rubies, and three amethysts. Also, each ending of the Gnomish Mines has several guaranteed gems, at least a luckstone and an amethyst.

Finally, most valuable gems cannot be generated in the main dungeon above certain dungeon levels (at level generation time), see the gems and Luck spoiler for details. Soft gems found in the early game are likely to be glass, and if they are expensive to buy back, they are worthless. (Valuable $2000 gems start at level 7, $2500 at 10, $3000 at 16, pricier even deeper.)

Some players type-#name all gems to take advantage of this and of the fact the hardness/color/price/isglass quadruple is unique for each type of gem.

Prices when unidentified[]

When selling gems which have not been formally identified to a shop, you will be offered a price from one of the "Unidentified Sell Price" columns. The values here will sometimes allow you to identify the gem. The column used is fixed for each shop (but may differ between shops), which may allow more gems to be identified if the column can first be determined.

The price table depends on compile time options. If you compiled Nethack yourself, check it is still valid.


Due to the existence of migohives, identifying four gems is slightly easier in SLASH'EM, due to the fact that only these gems are generated in migohives- the diamond, the ruby, the agate stone, and the fluorite stone. Hence, if you find a white gem in a migohive and can engrave with it, it's a diamond, and otherwise it's a fluorite stone. Blue, green, or purple gems found in migohives are also fluorite stones. If you find a red gem in a migohive, it's a ruby, and if you find an orange gem, it's an agate stone.

Alchemy with gems[]

Valuable gems can be dipped into potion of acid to make new potions. See Alchemy.