In reply to Jessica email, 18 karat gold is 18/24 parts gold.
Your second query: why the 2 gold chains differs so much in weight, although they are both 45 cm in length?
Both chains on your email are 18 carat gold hallmarks
The difference between these 2 chains is that Chain figure A is a solid chain and required more gold to fill up the thickness of the chain.
This type of chain is what we call “Hollow Gold” Your chain has an empty space inside.
This method is globally practised, the lesser gold use, the cheaper the item price will be.
A word of warning, because when the gold layer is so thin, regardless of its shape, these designs are beautiful, no doubt, but fragile because they can easily bend or else if knocked dents will appear so wear with care.
It is advisable to keep these items in individual boxes to avoid scratches and breakage