"Irogane" is the term for a set of Japanese metals and translates to "coloured metals".
Traditionally used from the XII century in sword-making and decorations.
Are all copper based metals, with added other metals in small percentages, like fine silver or gold.
With the traditional patination method "Niiro" they show different color, that improve over time.
Egyptian, Roman and Mycenaean finds, show the use of similar metals and patinations techniques, since 1850 a.C
for example:
"the crocodile from Fayum", dated to the 19th centuryBC, in the Ägyptische Sammlungcollection in Munich.
the statuette of the pharaoh "Amenemhat III" from the george ortiz collection, dated 1850bC.
the "Mensa Isiaca", dated 100aC, in the Egyptian museum of Turin, Italy.
Metal composed of 97% copper and 3% gold, after patination, the color turn black with purple reflections
With different grade of polish, the color change from a
velvety opaque to glossy compact black.
Metal composed of copper and silver, in different proportions.
The color varies from silver to dark gray.
Metal composed of Shakudo and Shibuichi in different proportions.
The color varies from brown to opaque black.
Mokume-gane translates closely to "wood grain metal", is a Japanese metalworking procedure which produces a mixed-metal laminate with distinctive layered patterns.
Mokume gane fuses several layers of differently coloured precious metals together to form a sandwich of alloys called a "billet.
The billet is then manipulated in such a way that a pattern resembling wood grain emerges over its surface.
