Humans have been creating jewellery for thousands of years. But, it has often proved challenging to find out exactly how long ago prehistoric humans started decorating items and using them as fashion accessories. One way for archaeologists to determine the date of an object is to look around the surrounding excavation site.
Here, the deeper layers are older and items close to each other usually prove to be the same age.
This is not always an accurate way to go about dating items: sometimes buried materials can move with changing climates or geological events, and so archaeologists more and more use the technique of radiocarbon dating to pinpoint the exact age of a piece of the past.
This is what researchers from Germany, Italy and Poland did in a study looking at the discovery of a decorated ivory pendant found in a cave among animal bones, finding that the ancient bling was 41,500 years old.
Every plant and animal contains small amounts of a radioactive form of carbon (C14), but when they die, the C14 gradually decays.
Because the rate of radioactive decay is constant overtime, it is possible to make a reasonable estimate of the materials that originated from plant or animal materials by measuring the C14 that is left in the material today.
Modern methods of radioactive decay are enabling researchers to make more accurate estimates by the day.
Because the object found in the cave is the earliest known evidence of humans decorating jewellery to be found in Eurasia, it could represent the emergence of the behaviour in human evolution, according to the researchers.
Excavations in Stajnia Cave, Poland, in 2010 first uncovered the item.
Reporting their techniques in an article in Scientific Reports, the team described sending the samples to two separate radiocarbon dating labs.
Both labs came back with similar results.
Dr Wioletta Nowaczewska of Wrocław University, a co-author of the paper, told BBC Science Focus magazine: “This piece of jewellery shows the great creativity and extraordinary manual skills of members of the group of Homo sapiens that occupied the site.
“The thickness of the plate is about 3.7 millimetres, showing an astonishing precision on carving the punctures and the two holes for wearing it.”
The team has not yet been able to identify exactly, if anything, the pattern is supposed to represent.
Dr Nowaczewska added: “If the Stajnia pendant’s looping curve indicates a lunar analemma [a diagram depicting the movement of the Moon in the sky] or kill scores will remain an open question.”
The researchers now plan to carry out detailed analyses on other ivory objects found in Stajnia Cave.
Studies of other sites in Poland are currently underway and promise to yield more insights into the strategies of production of personal ornaments in Central-Eastern Europe.
While the pendant is the oldest jewellery found on the Eurasian continent, it still pales in comparison to some of the items found in Africa.
But, it dates back to the Palaeolithic era, when modern humans started to settle across Europe.
While its age is known, many questions remain about the pendant.