Antique outlet Amethyst Glass and Silver Necklace

This is a piece of Portland Oregon history! The glass cabochon was cut from Amethyst light blocks from the old sidewalks in downtown Portland, Oregon. In the late 1800's, Portland was a port city on the banks of the Columbia river with a complete network of underground tunnels known as the Shanghai tunnels! Being that the city was still using natural gas to light the streets at night, they used glass blocks set in the sidewalks to allow light to pass through into the tunnels. The glass blocks were clear glass when originally set, but over the past 100+ years of being under the sun (UV light) the antique glass turns a beautiful Amethyst Purple from oxidation of Manganese used in the glass to make it clear ( the glass recipe changed around 1920's outlet effectively eliminating the Amethyst oxidation reaction). The blocks were only used in a handful of cities across the US so they are a very unique and rare! These blocks were salvaged in the 1970's from demolition projects in downtown Portland, Oregon. I received the glass from a close friend that was on the demolition projects and had the good sense to put them aside for historical preservation. I cut the glass down into a custom cabochon then build each piece to order. Here is an opportunity to own a rare piece of Portland, Oregon history!