Russia

From the Romanov era, period of Tsar Alexander II, in gold, the front decorated with a guilloché or engine turned pattern centring a pearl, the reverse of polished gold. 

Moscow, 1868, hallmarked, chain not included

Cross measures 1 5/8 in. (4.1 cm) long, including outer ring; 7/8 in. (2.2 cm) across. 

Pattern scratched in a small area below pearl, small fissure on reverse.