Hepatizon
Encyclopedia
Hepatizon also known as Black Corinthian Bronze, was a highly valuable metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...

 alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

 in classical antiquity
Classical antiquity
Classical antiquity is a broad term for a long period of cultural history centered on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome, collectively known as the Greco-Roman world...

. It is thought to be an alloy of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 with the addition of a small proportion of gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

 and silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

 (perhaps as little as 8% of each), mixed and treated to produce a material with a dark purplish patina
Patina
Patina is a tarnish that forms on the surface of bronze and similar metals ; a sheen on wooden furniture produced by age, wear, and polishing; or any such acquired change of a surface through age and exposure...

, similar to the colour of liver. It is referred to in various ancient texts, but no known examples of hepatizon exist today.

Of the known types of bronze
Bronze
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

 or brass
Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...

 in classical antiquity (known in Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 as aes and in Greek as χαλκός), hepatizon was the second most valuable. Pliny the Elder
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

 mentions it in his Natural History
Naturalis Historia
The Natural History is an encyclopedia published circa AD 77–79 by Pliny the Elder. It is one of the largest single works to have survived from the Roman Empire to the modern day and purports to cover the entire field of ancient knowledge, based on the best authorities available to Pliny...

, stating that it is less valuable than Corinthian bronze
Corinthian bronze
Corinthian bronze, also called Corinthian brass or æs Corinthiacum, was a highly valuable metal alloy in classical antiquity. It is thought to be an alloy of copper with gold or silver , although it has also been contended that it was simply a very high grade of bronze, or a kind of bronze that...

, which contained a greater proportion of gold or silver and as a result resembled the precious metal
Precious metal
A precious metal is a rare, naturally occurring metallic chemical element of high economic value.Chemically, the precious metals are less reactive than most elements, have high lustre, are softer or more ductile, and have higher melting points than other metals...

s, but was esteemed before bronze from Delos
Delos
The island of Delos , isolated in the centre of the roughly circular ring of islands called the Cyclades, near Mykonos, is one of the most important mythological, historical and archaeological sites in Greece...

 and Aegina
Aegina
Aegina is one of the Saronic Islands of Greece in the Saronic Gulf, from Athens. Tradition derives the name from Aegina, the mother of Aeacus, who was born in and ruled the island. During ancient times, Aegina was a rival to Athens, the great sea power of the era.-Municipality:The municipality...

. As a result of its dark colour, it was particularly valued for statue
Statue
A statue is a sculpture in the round representing a person or persons, an animal, an idea or an event, normally full-length, as opposed to a bust, and at least close to life-size, or larger...

s. According to Pliny, the method of making it, like that for Corinthian bronze, had been lost for a long time.

Similar alloys are found outside Europe. For example, shakudo
Shakudo
Shakudō is a billon of gold and copper , mostly designed for its dark blue-purple patina. It was historically used in Japan to decorate katana fittings such as tsuba and kozuka...

 is a Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese billon
Billon (alloy)
Billon is an alloy of a precious metal with a majority base metal content . It is used chiefly for making coins, medals, and token coins.The word comes from the French bille....

of gold and copper with a characteristic dark blue-purple patina.

Lichen

  • Cetraria hepatizon
  • Melanelia hepatizon
  • Lichen hepatizon
  • Parmelia hepatizon
  • Platysma hepatizon
  • Tuckermanopsis hepatizon

Sources

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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