The single loop-in-loop chain is one of the oldest chain styles. Some of the oldest examples date back to 3,000 BCE from the burials at Ur. The simple loop-in-loop style stayed static until around the time of the Hellenistic period. During this time the Greeks and Etruscans expanded on the single loop-in-loop to create a double loop-in-loop, pinched loop-in-loop, two- way double loop-in-loop, three-way double loop-in-loop, “S” Link, woven loop, and other variants. The chains found from this time often have something elaborate about them, either a clasp or a pendant. Here are some examples:
Classic Loop-in-Loop Chain
Pinched Loop Chain

Double loop-in-loop Chain

The Metropolitan Museum of Art
Triple Loop-in-Loop Chain

©The Trustees of the British Museum
Three-Way Double Loop-in-Loop Chain
Round-Sectioned Loop-in-Loop Chain

©The Trustees of the British Museum
Double Figure-of-Eight Chain

©The Trustees of the British Museum
Single Figure-of-Eight Chain

“s” link Chain
The Metropolitan Museum of Art © The Trustees of the British Museum
The “s” link is found on many bead and chain necklaces. However, according to Ogden, this was not an ideal form for a connector as it was not nearly as secure as the loop-in-loop chains which are soldered. Soldering was possible but difficult as it had to be done after the necklace was assembled. It was also not nearly as strong, something of concern given the expense of gems and in the case of some necklaces, the weight.