A gold cross pendant can range from a simple white gold cross to a diamond encrusted miniature ornate casting in solid gold of Jesus Christ on the Cross.
Some will have diamonds set in them or even pearls, opals and other gems such as rubies, or emeralds etc.
As this is most often worn for long periods it is wise to select one that is long wearing and durable. 14 or 10 carat gold would be the most suitable as the gold is alloyed with other metals to make it stronger. A 24 carat gold cross pendant would be far too soft and, as well as wearing away quickly, being such a delicate object, is likely to become distorted with such extensive use.
There are thousands of different styles and types to chose from and it can only be left up to you what type or style you feel is most suitable or appropriate both as a fashion accessory and as a religious symbol.
Cleaning such a delicate object requires some care and attention. Use only clean water and an old soft toothbrush to get any dirt particles out from the crevasses. Wash over a bowl, not the sink. You don’t want your valuable piece to en up down the plug hole. Make sure the piece is fully dry before you put it away or wear it again. Even though the cross may be gold the clasp may be other metal and you do not want it to tarnish or rust.
When you put it away ensure it is put separate from other jewellery, especially diamonds, as they can scratch the piece so easily.
So having a gold cross pendant can be a very good proclamation of faith provided it is well looked after and cared for.