There is no historical record that suggests Tiberius executed a man out of fear that glass would devalue gold and silver. Tiberius was a Roman emperor who reigned from 14 AD to 37 AD, and while he was known for his distrust of the Roman Senate and his inclination towards tyranny, there is no evidence that he executed someone for this reason.
Furthermore, the idea that glass would devalue gold and silver is not historically accurate either. While glass was a relatively new and expensive material in ancient Rome, it was not seen as a replacement for precious metals such as gold and silver. Instead, glass was used for decorative objects, tableware, and architectural purposes. In fact, glass was often decorated with gold and silver to make it even more valuable.
It is important to rely on credible historical sources and to fact-check information before accepting it as true.
To be fair, historical peoples didn’t look at the value of things the same way that we do. So, it’s entirely possible that, if Tiberius was exposed to this glass, that he might see it as an interference to his earthly wealth. The elites of our societies have often hindered societal advancements out of self-interest to their wealth and position.
Also to add, if it existed, it may have been glass-like but not actually made out of silicate, but something else that looked like glass.
There are two historical accounts of this event. One from Pliny and another from Roman Courtier and it’s considered satirical.
Several decades ago I heard a slightly different version. A glass-maker produced clear window-panes, which no one else could match. So, his competitors complained to the emperor, who had him executed.