Short answers, pulled from the story.
A law dated the 8th of November, 1291 confined most of Venice's glassmaking industry to the island of Murano. The move reduced fire risk in Venice and allowed the government to control the spread of glassmaking secrets.
Cristallo is a soda glass developed by Murano glassmaker Angelo Barovier during the fifteenth century. It was considered Europe's clearest glass and so closely resembled carved rock crystal that the name arose from the comparison. The oldest surviving reference to cristallo is dated the 24th of May, 1453.
The Venetian government confined glassmakers to Murano to prevent their skills and secret recipes from reaching competitors. Leaving without permission was punishable by death, and earlier guild rules specified that a worker's family would be imprisoned and an assassin sent if the worker refused to return.
Murano glassmakers held elevated social status and were under the direct rule of Venice's Council of Ten. An announcement on the 22nd of December, 1376 declared that a glassmaker's daughter who married a nobleman would suffer no loss of social class, and their children would be nobles.
Venetian glass trade beads were found in February 2021 at three prehistoric Inuit sites in Alaska, including Punyik Point. Radiocarbon dating of nearby materials placed their arrival between 1440 and 1480. Researchers believe they traveled overland from Venice across Eurasia and over the Bering Strait, though the dating has been challenged by some scholars who favor a mid-sixteenth-century or early seventeenth-century origin.
Several forces converged to weaken Murano: the 1612 publication of L'Arte Vetraria exposed glassmaking secrets, skilled workers emigrated to serve foreign monarchs, and English and Bohemian glassmakers developed lead crystal and lime-chalk glass that proved more popular than cristallo by the 1700s. Napoleon closed the Venetian glass factories in 1807, and recovery began only after Venice joined Italy in 1866.