The young
open cluster NGC 6530 associated with the Lagoon Nebula M8 was classified as of Trumpler type «II 2 m n» (see e.g. the Sky
Catalog 2000), meaning that it is detached but only weakly concentrated toward its center, its stars scatter in a moderate range of brightness, it is moderately rich (50 — 100 stars), and associated with nebulosity (certainly, with the Lagoon nebula).