Looking Closer at Glass Fragments

Hey guys!

Over this last summer at FSJ we uncovered a lot of glass shards. These shards ranged from the size of a pushpin to the size of a poker chip and the colors we found were just as diverse. The most common colors were clear, olive green, light blue, and dark blue. I found these differences in glass to be very interesting. I always took glass for granted. To me, glass was something that was clear and never thought about, but to the French it was much more. Glass held their medicine and drinks for example. I wanted to shed a light on a part of material culture that is usually overlooked in archaeological analysis. I aim to analyze the many different shards of container glass and find out where the densities of different types of glasses are in order to find out more about french colonial culture. 

The first question I needed to figure out in my research was “why are glass containers different colors?” In the Archaeological Analysis class, where me and several other students are currently taking a closer look at the artifacts found at FSJ, we received a packet that contains a lot of useful information about glass manufacturing and a whole section on glass color! As it turns out, glass gains its color by the burning of impurities in the sand used to make it. But what impurities in the sand create the colors we see at the fort? The green hue in some of the glass specimens is caused by naturally occurring iron oxides within the sand. An olive green hue to glass was considered to be the natural color of glass. Blue glass on the other hand is the result of copper in the sand and it could be recreated by adding cobalt oxide to the melding pot when making the glass. 

I will use the glass colors to create subgroups and help organize my research. The next phase of my research has me looking over the vast amount of container glass shards that have been found at FSJ and grouping glass by color will be very helpful. Glass color and manufacturing techniques is a whole rabbit hole and I cannot wait to learn more about it in my research! I will make another blog soon with more interesting facts about glass.and updates on my research. 

Until then,

-Ian

For more information about glass colors: https://sha.org/bottle/colors.htm