These earrings look very Art Deco to me, but their listing at S.J. Philips doesn’t mention a date, so I’m assuming they’re contemporary or their date is unknown.
Either way, they’re gorgeous – a more creative take on the standard chandelier diamond earring, with the graduated brilliant cut diamonds increasing in size down to the final fringe.

These earrings are currently for sale at S.J Philips. All images and info are thanks to S.J. Philips.