Well-made vintage Spider brooch, 

likely made in the early to mid-c20th in an older style.

Large brooch, textured silver-tone metal set with faceted Aurora borealis type crystals / rhinestones.

(gentle rainbow.effect crystals).

The metal might be silver but no marks and if it is, then not a sterling grade.

Safety catch pin.

About 5.8cm long.

Does need some polish / clean but otherwise very good condition.