6.1 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| History of glass | 3/5 | https://en.wikipedia.org/wiki/History_of_glass | reference | science, encyclopedia | 2026-05-05T03:59:48.666461+00:00 | kb-cron |
In China, glass played a peripheral role in arts and crafts when compared to ceramics and metal work. The earliest glass items in China come from the Warring States period (475–221 BCE), although they are rare in number and limited in archaeological distribution. Glassmaking developed later in China compared to cultures in Mesopotamia, Egypt and India. Imported glass objects first reached China during the late Spring and Autumn period (early 5th century BCE), in the form of polychrome eye beads. These imports created the impetus for the production of indigenous glass beads. During the Han Dynasty (206 BCE–220 CE), the use of glass diversified. The introduction of glass casting in this period encouraged the production of moulded objects, such as bi disks and other ritual objects. Chinese glass objects from the Warring States and Han period vary greatly in chemical composition from the imported glass objects. The glasses from this period contain high levels of barium oxide and lead, distinguishing them from the soda–lime–silica glasses of Western Asia and Mesopotamia. At the end of the Han Dynasty (AD 220), the lead-barium glass tradition declined, with glass production only resuming during the 4th and 5th centuries AD. Literary sources also mention the manufacture of glass during the 5th century AD.
=== Roman World ===
Roman glass production developed from Hellenistic technical traditions, initially concentrating on the production of intensely colored, cast glass vessels. Glass objects have been recovered across the Roman Empire in domestic, funerary and industrial contexts. Glass was used primarily for the production of vessels, although mosaic tiles and window glass were also produced. However, during the 1st century CE, the industry underwent rapid technical growth that saw the introduction of glass-blowing and the dominance of colorless or ‘aqua’ glasses. Raw glass was produced in geographically separate locations to the working of glass into finished vessels, and, by the end of the 1st century CE, large scale manufacturing, primarily in Alexandria, resulted in the establishment of glass as a commonly available material in the Roman world.
=== Islamic world ===
Islamic glass continued the achievements of pre-Islamic cultures, especially the Sasanian glass of Persia. The Arab poet al-Buhturi (820–897) described the clarity of such glass: "Its color hides the glass as if it is standing in it without a container." In the 8th century, the Persian-Arab chemist Jābir ibn Hayyān (Geber) described 46 recipes for producing colored glass in Kitab al-Durra al-Maknuna (The Book of the Hidden Pearl), in addition to 12 recipes inserted by al-Marrakishi in a later edition of the book. By the 11th century, clear glass mirrors were being produced in Islamic Spain.
=== Africa ===
Evidence suggests that indigenous glass production existed in West Africa well before extensive contact with other glassmaking regions. The most significant and well-documented example is the Ife Empire of Southwestern Nigeria. Archaeological excavations at Igbo Olokun, a site in northern Ife, have yielded a substantial quantity of glass beads, crucibles, and production debris dating from the 11th to 15th centuries CE. Chemical analysis revealed a unique chemical signature significantly different from known imported glass types. The Igbo Olokun glass is characterized by a high-lime, high-alumina (HLHA) composition, reflecting the use of locally sourced raw materials, likely including granitic sands and possibly calcium carbonate from sources such as snail shells. At least two distinct glass types, HLHA and low-lime, high-alumina (LLHA), were produced at Igbo Olokun. Colorants including manganese, iron, cobalt, and copper were intentionally added to produce a range of colors, most notably various shades of dichroic blue and green. Analysis also revealed the presence of glass production waste, including fragments of crucibles bearing vitrified glass residues, confirming the onsite nature of the manufacturing.
=== Medieval Europe ===
After the collapse of the Western Roman Empire, independent glass making technologies emerged in Northern Europe, with artisan forest glass produced by several cultures. Byzantine Glass evolved the Roman tradition, in the Eastern Empire. The claw beaker was popular as a relatively easy to make but an impressive vessel that exploited the unique potential of glass. Glass objects from the 7th and 8th centuries have been found on the island of Torcello near Venice. These form an important link between Roman times and the later importance of that city in the production of the material. Around 1000 AD, an important technical breakthrough was made in Northern Europe when soda glass, produced from white pebbles and burnt vegetation was replaced by glass made from a much more readily available material: potash obtained from wood ashes. From this point on, northern glass differed significantly from that made in the Mediterranean area, where soda remained in common use. Until the 12th century, stained glass – glass to which metallic or other impurities had been added for coloring – was not widely used, but it rapidly became an important medium for Romanesque art and especially Gothic art. Almost all survivals are in church buildings, but it was also used in grand secular buildings. The 11th century saw the emergence in Germany of new ways of making sheet glass by blowing spheres. The spheres were swung out to form cylinders and then cut while still hot, after which the sheets were flattened. This technique was perfected in 13th century Venice. The crown glass process was used up to the mid-19th century. In this process, the glassblower would spin approximately 9 pounds (4 kg) of molten glass at the end of a rod until it flattened into a disk approximately 5 feet (1.5 m) in diameter. The disk would then be cut into panes. Domestic glass vessels in late medieval Northern Europe are known as forest glass.
==== Anglo-Saxon world ====