A skill-specific small XP lamp is a common prize reward from Treasure Hunter, which grants the player a definite amount of experience scaled to the selected skill level. The experience gained is the same from level 98 to 120. Lamps can be gained for any skill that has not been frozen.
In addition to coming in a skill-specific form, where the skill was specified by the lamp, players could also receive lamps where they could choose the skill they'd gain experience in. These were replaced on the Squeal of Fortune with small prismatic lamps.