This is a natural Ethiopian opal necklace (not "lab grown" or "simulated"). Ethiopian opals are loved for the way they reflect light which results in a constant play of color within the beads. In the spiritual realm, the opal's characteristic spectrum of color is thought to bring harmony and balance. Adjustable from 16" to 18" Total weight is 6.91 grams Opals are slightly graduated from 3.6mm to 4.7mm Lobster Clasp marked 925 New/never worn condition Bundle to save more!!