Quote (Stories @ 5 Oct 2018 18:40)
Items will disappear or poof after a certain amount of time if left on the ground. Here is a direct quote from Arreat Summit:
10 minutes: Keys, Potions, Scrolls, Tomes, Arrows/Bolts.
10 minutes: Any Armor and/or Weapon of quality; magic, regardless if flagged as ''Ethereal'', ''Socketed'' or not. This includes rune words!
10 minutes: Pandemonium artifacts such as the Key of Terror/Hate/Destruction and Mephisto's Brain, Diablo's Horn, Baal's Eye.
10 minutes: Essences and Token of Absolution (These are new items from Patch 1.13).
20 minutes: Magic Items, Gems and Runes.
30 minutes: Rares, Set Items, Uniques and Crafted Items.
Picking an item up with your cursor/mouse will reset the timer.
Nebu (Geoff Fraizer) applied that update to the Arreat Summit website on 25 Feb 2011 (~ 7.5 years ago).
Quote (pwb3 @ 8 Oct 2018 21:14)
I knew that for over a decade.
Launch date of 1.13a PTR: 10 Dec 2009.