Cranberry glass, traditionally called ruby glass in Europe, is made by adding gold salts (technically, gold chloride) to batches of molten glass. Gold is what gives cranberry glass its pink to red hue. The more gold that is used, the deeper the red, but the amount of gold used in even the reddest cranberry glass is minor, which is why color alone is not a factor in the price of vintage cranberry glass. While variations of the technique to...Continue Reading