3.5cm by 2.5cm YES.
Total length with the chain when on is 23cm.
Each necklace has either gold or silver plated chain and jewellery findings.
The acrylic is hard wearing and durable, but to ensure the quality please avoid contact with direct heat and strong chemicals and just clean with a damp cloth. Always store and transport your jewellery in its box. Keep water, perfume and other sprays and lotions away from your jewellery, as moisture can discolour metal parts. I advise cleaning metal parts with a silver and gold cleaner/tarnish protector after every use.