Glass

"The true impact of glass cannot be understated. Even with the introduction of plastics (and our more modern bioplastics), glass is still the only material known to never interact with magic. Because of this, glass is the only material which can be safely used to store potions, ingredients, and experimental substances without fear of contamination or vessel degradation. Do not be fooled by its fragility and commonplace nature. Glass is more valuable to the discerning magic user than gold or even Aranis silk."
Ferdinand Koffza, author of A Brief History Of Industrial Materials

Manufacturing process

Prior to industrialisation, glass blowing was one of the few careers which non magical people could choose if they wanted a career in the Symposium. The benefits of becoming a glass blower were numerous, as not only was it well paid, but it allowed for networking between traditional Symposiasts and non magical people. As well as making potion bottles and ingredients containers, more skilled glass blowers were selected to work on embellishments for the Symposium. Glass blowers could go on to make elaborate lighting fixtures, beautiful sculptures, and the most elegant dinnerware.

Significance

On Saga, glass is an incredibly sought after material. Whilst there are other materials which can store magic, plastics and metals and biological substances often react with the substance held inside, and are often far more expensive. Because of its importance to magic users, the Symposium still runs and operates a glass blowing workshop. These days it focuses more on decorative containers, but prior to the revolutionary technological shift which allowed the mass production of potions bottles, the workshop was vital to the studies of the Symposium.

Rarity

A full set of glass dinnerware made by modern masters would still attract a high price from bidders whether it was made centuries ago or yesterday. The important quality is not the age of the set, but rather the skill and reputation of its creator.