Weathered Copper Bulb is the third oxidation stage in the copper bulb family, one step past Exposed Copper Bulb and one step before Oxidized Copper Bulb. A single redstone pulse toggles Weathered Copper Bulb between lit and unlit instantly, with no continuous power required to keep the light on. Weathered Copper Bulb emits light level 8 while lit, compared to 15 on the base Copper Bulb, 12 on Exposed Copper Bulb, and 4 on Oxidized Copper Bulb. Weathered Copper Bulb requires a Stone Pickaxe or better, and a weaker tool leaves no drop at all. Lightning and an axe strip one oxidation stage from Weathered Copper Bulb, while Honeycomb wax stops any further oxidation entirely.

A comparator placed beside Weathered Copper Bulb outputs signal strength 15 during the lit state and 0 during the unlit state, regardless of the oxidation stage. An observer detects the exact moment a redstone pulse powers or unpowers Weathered Copper Bulb, useful for triggering additional circuits. Comparator plus Weathered Copper Bulb forms a compact T flip-flop, because the comparator reacts only to the lit state rather than to raw redstone power. Three Weathered Copper Block, one Blaze Rod, and one Redstone Dust craft four Weathered Copper Bulb at once, matching the natural spawns of lit, waxed bulbs in random oxidation stages inside Trial Chambers. Builders who want dimmer accent lighting than a fresh Copper Bulb, without two extra weathering stages, can craft Weathered Copper Bulb directly for that effect.