Hi, this is my maiden post on this board. I'm a complete newbie to pearls, having only developed an interest in them in the last few months or so. I recently purchased a pearl necklace by Mikimoto bearing the description of a graduated 9x7mm A1 necklace. I'm unsure what 9x7mm means - does it mean the necklace has 9 7mm pearls and these pearls are the biggest in the entire strand? The sales assistant (we had bought the necklace onboard a cruise ship) was quite clueless (although since we were equally clueless, we bought into everything he said!) - he told us that A1 pearls are between A and A+ pearls in the Mikimoto universe and that 9x7mm means the largest pearl in the entire diamond strand is 9mm, which the rest of the pearls between 7-9mm. We totally believed him until I went to the Mikimoto website after our holiday and saw that a 7-7.5mm A1 necklace (US$3750) was retailing for more than the 9x7mm necklace (US$3500), which triggered off alarm bells. I love my necklace but would be grateful for insight as to what I actually bought; I tried trusty google but it yielded nothing helpful and we don't live near a mikimoto boutique (we are not in the USA). Thank you very much!