This is a diamond cut, rope chain necklace. This is a traditional style necklace that has a 4 millimeter thickness. Rope chains are known to be extremely strong and sturdy and can usually hold any large or heavy charms. If your charm bail is the same size as the rope chain thickness, then the charm will not fit through. This necklace is .925 sterling silver. It is very common that this necklace could turn your neck black or green if you are allergic to silver copper alloy or if you have very high acidic skin.