Vintage Unique Onyx, Obsidian, and Metal Necklace

What goes with most wardrobes? Black, gray, silver, and white! All colors which can be found in this beautiful, unique three layer necklace. It was my nana's and given the sheer amount of jewelry I am keeping of hers, some of it, including this piece, had to go. The metal is not silver as far as the jeweler who checks all my pieces could tell, but the stones seem to be obsidian, onyx, and possibly hematite. It measures 11 inches from the clasp to the middle of the first strand; 11.5 inches to the middle of the second; 12.5 inches to the middle of the third and bottom strand. It is in excellent, preowned vintage condition