Brass is how a range of copper-zinc alloys are called. Its main ingredient is copper and, depending on how much zinc it is combined with, its color and hardness will vary. When not covered with any sort of coating, this metal naturally develops some tarnishing, named patina, on its surface.
More often than not, the looks of a brass instrument covered in patina are appealing to those who cherish the visual effects of time indicating the object has a story to tell.
Zippo and medal made of brass, tarnished. Photo credit: Kevin O'Mara. – CC-BY-SA-2.0
The success of brass in general applications stems not only from its beauty, but also from its non-ferrous composition. Thanks to this valuable characteristic, brass does not rust, and is typically resistant to the corrosive effects, including those of salt water.
US Navy sail master shouting commands using a traditional brass speaking horn. Photo credit: AIRMAN Nick Lyman – Public domain
As brass is a highly sustainable material, it has been used in different forms since prehistoric times.
A few occurrences of early copper-zinc alloys that date from the 3rd millennium BC have been found in Western Asian territories.
The earliest brass alloys may have been attained by the smelting of copper ores with a higher concentration of zinc, which resulted in alloys with highly variable compositions.
Copper ore from the Precambrian of South Africa. Photo credit: James St. John – CC-BY-SA-2.0
It is presently considered that brass was sometimes made involuntarily, and there is an interesting explanation for that. Antique brass objects presented tin contents quite similar to those found in bronze at that time. Also, it is not rare to find zinc and tin ore deposits together, and these two elements share similar properties and colors.
On the left, sphalerite, the most important ore of zinc. On the right, cassiterite, a tin oxide mineral. Photo credit: James St. John – CC-BY-SA-2.0; Rob Lavinsky – CC-BY-SA-3.0
However, a large number of these objects have been found with more than 12% of zinc. This concentration results in that distinctive golden color that catches our eyes, which suggests that at least some of those artifacts were intentionally manufactured in a form of brass.
But brass was not easily produced,
and that is why you may have heard of a Copper Age, a Bronze Age, and an Iron Age, but not of a Brass Age.
In the past, up to the 18th century, because pure zinc metal has melting and boiling points that were extremely high for the technology available at that time, it was not possible to be made.
Melting crucible. Photo credit: @Skatebiker via English Wikipedia – Public domain
To overcome this challenge, calamine was the key.
Calamine, or ground smithsonite ore, contains various zinc compounds. It used to be added into a crucible with copper and the mixture was heated until calamine was reduced to metallic state. In spite of copper not being melted at this point, it was permeated with zinc vapor. This new compound, after melting, resulted in an uniform alloy – calamine brass.
The technique described above is called cementation, and variations of which were kept in use from the Roman period to the mid-19th century.
Smithsonite / Calamine, from Norman and Gertrude Pendleton mineral collection. Photo credit: @Cs california via Wikimedia Commons – CC-BY-SA-3.0
In the 1st century BC, Romans, who referred to brass as golden copper, had enough supply to make coins and military equipment – especially helmets. Brass would also be the choice to the crafting of decorative objects, musical instruments, and ornamental jewelry of all kinds. All these items had zinc concentrations that varied from 11% to 28%, a relatively impressive number for the methods available at that time.
A sestertius of Roman emperor Hadrianus. Diameter 32mm. Weight 25g. Found in the river Garonne near Bordeaux in 1965, from a shipwreck in ~155 CE. Photo credit: @Jebulon via Wikimedia Commons – Public domain
From then on, the production of brass evolved in different ways. It has been long way down until we got to the brassware we have available nowadays. This journey of hundreds of years was definitely worth pursuing and led us to this moment. Now we have access to an exquisite and impressive set of creations machined from solid brass! Feel free to navigate through our catalog and check some of them.