This 8^th century necklace made of gold and glass beads is currently in the lab for examination and cleaning. Although extremely old and delicate, the gold still shines bright. Gold is a very stable metal and does not corrode and tarnish like copper or silver. Even ancient gold often looks brand new. The ancient glass beads are another story. The three components of most ancient glasses are soda, lime, and silica. Though the main ingredients were known when these beads were made, the chemistry of glass-making was not fully understood; impurities and irregular mixtures of ingredients led to unstable glass that corrodes over time. On the right, you can see a magnified image of one of the beads.  The khaki green coating is a corrosion crust that is crumbling, and underneath this layer you can see a red glass with an iridescent degradation product. If allowed to continue, this glass bead could degrade into a powdery pile of corrosion products. Our objects conservator will be working to stabilize the glass so that the beads will have a brighter future. Once conservation is finished this necklace can be seen on display in Gallery 149.

Image Credit: Necklace, Northern Iran, 8^th Century BCE – 7^th Century BCE, gold hoop with gold-capped frit beads, Cincinnati Art Museum, Museum Purchase, 1953.66.