The Thieving casket contains a variety of skilling resources, but more importantly, skilling outfit pieces.

Thieving casket
ExamineMay contain a rogue's outfit or warez.
Properties
TradeableNo
EquipableNo
StackableNo
NoteableNo
OptionsOpen, Drop
Values
Value0 coins
AlchemyNot alchemisable
Weight5 kg
Advanced data
Item ID? (edit)

Each individual piece will provide a 2% Experience boost while training Thieving, with the exception of the gloves and boots that only provide 1%. While wearing the full set another 2% bonus is applied, in total providing a 10% Experience boost.

Shops

Seller Item Amount in stock Price sold at
Skilling Points shop   Thieving casket 50,000 Skilling points
AFK Tokens shop   Thieving casket   1,000
Source Level Item Quantity Rarity
Event chest N/A   Thieving casket 1 Uncommon
Sponsor treasure N/A   Thieving casket 1 Uncommon

Rewards

Always Drops

Item Quantity Rarity Price High Alch
 Coins100,000Always100,000100,000
 Thieving tome1AlwaysNot soldN/A

Common Drops

Item Quantity Rarity Price High Alch
 Coins250,000Common250,000250,000
 Uncut sapphire100Common260,0001,500
 Uncut emerald100Common420,0003,000
 Uncut ruby100Common680,0006,000
 Thieving tome1CommonNot soldN/A

Uncommon Drops

Item Quantity Rarity Price High Alch
 Uncut diamond100Uncommon1,080,00012,000
 Uncut dragonstone50Uncommon4,450,00030,000
 Thieving tome1UncommonNot soldN/A

Rare Drops

Item Quantity Rarity Price High Alch
 Uncut onyx1Rare1,000,000120,000
 Rocky1RareNot soldN/A

Very Rare Drops

Item Quantity Rarity Price High Alch
 Rogue mask1Very rare; 1/5Not soldN/A
 Rogue top1Very rare; 1/5Not soldN/A
 Rogue trousers1Very rare; 1/5Not soldN/A
 Rogue gloves1Very rare; 1/5Not soldN/A
 Rogue boots1Very rare; 1/5Not soldN/A