Definition: The word "alum," which is also known as alumina or alum, refers to a high-temperature metal that forms a hard and brittle ceramic material when heated. It can be used in a variety of applications such as ceramics, construction materials, and industrial processes.
Alumina's crystal structure consists of 24 face-centered cubic (fcc) hexagonal lattice planes, which are arranged into a three-dimensional honeycomb. The alumina crystals have a high melting point and low thermal conductivity, making them suitable for use in the manufacture of ceramics, thermoplastics, and ceramic substrates. They can be found in various alloys, such as aluminum or magnesium-aluminum, and are often used in aerospace components, construction materials, and industrial equipment.
The word "alum" also has other meanings in the Bible and in ancient texts:
- In Greek mythology, alum was an offering made to Poseidon (the king of the sea) by a priestess called Pallas.
- In Old English, "alum" was used to refer to a type of wood that is known as alderwood or alabaster. It is now commonly used in ceramics and other materials.
- In Hebrews 6:14, Jesus said, "And the foundation of the wall of God did not set its foundations on earth, but on an island."
- The word "alumina" also has a figurative meaning in Greek mythology; it was used as a symbol to represent the dark aspects or corruption of the good.
- In the New Testament, some Christians use "alum" in reference to the blood Jesus shed for them.
The exact meaning and usage of "alum" are somewhat debated among scholars due to its ambiguous etymology. However, it is often seen as a symbol of sacrifice and redemption, with both metaphorical and literal meanings depending on the context.
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