I have an 18ct gold chain which is really too short for me. With the price of gold being what it is & the cost of buying a longer chain I was considering buying a chain extender. What I would like to know is ... could I use a 9ct extender, or would this wear away at the main chain as it is a harder gold? Also can anybody recommend a place where I could buy such a thing? Hoping somebody can help & point me in the right directon!