Thin glass and as much pigment as possible.
At the end of his life, Monet was nearly blind and basically abstract. Those paintings barely pretend to represent anything but paint, just a master colorist at the end of his life paring down to the six pigments he loved most. This necklace is more pigment than glass, an equally thin excuse to devote full focus to a beloved color.
Pure fine art pigment in quartz glass, set in precision machined black anodized aluminum and attached with a ribbed magnetic clasp.