Antique Necklace, Gold and Coloured Teardrops

This fine, elegant vintage necklace with pear-shaped pastel coloured drops, gemstones or glass, is on what looks like a rose gold chain, with marking on the link hard to read, but appears to be 11 and maybe a letter.

I understand that a gold chain marked "11" likely indicates it's 11 karat gold - perhaps this is a European mark?

Donated to my service club by a 93 year old lady, and I believe it was her mother in law's so quite an age to it. Anyone familiar with the mark? Thanks in advance!!