A LED lamp has a base and an at least partially optically transmissive enclosure connected to the base. A heat sink is partially disposed in the enclosure and supports a plurality of LEDs. The heat sink comprising a mounting portion positioned in the enclosure for supporting the LEDs and a heat dissipating portion exposed to the ambient environment where the interior of the enclosure is exposed to the ambient environment. The heat sink have a plurality of separate heat sink structures that are mounted to the lamp independently of one another. Each heat sink structure may have a thickness of approximately 1-5 mm. Each heat sink structure may in some embodiments weigh approximately 3.8 to 7.7 grams and in other embodiments weigh approximately 27 grams.