Welcome to the club in terms of being dropped by Google. If you read around the forum--you've got alot of company. And none of us knows why. Good quality sites with no HTML errors and great content are being dropped. The theory around this forum is--pony up those Adwords $ or adios--no more "freebies". Did you just turn off (or reduce) your Adwords listing? We've noticed our delisting coincided with it. So we concur with the postings. Google wants money now for listings.
I did pull up your site and look at the source. I've never seen so many carriage returns. Hidden characters (like "end of line", really do have a character to a computer, even tho' it's not visible to us). Maybe the spiders don't know what to make of it either. Not sure if it'd make any difference????
You were also missing a DOCTYPE tag which would tend to indicate you're not using valid HTML. It's a BORING, LABORIOUS task to clean up your HTML, but I know for a fact it'll help your ranking in MSN and probably the others as well. And you'll probably find that your MSN and Yahoo traffic will increase with your Google delisting, so my suggestion is spend your time on improving in the secondary engines until Google gets their act together (or everyone flees, screaming like Banshees from their website which is lower in relevance than either MSN/Yahoo in our opinion, and and growing heavily commercial).
Design input? You might try updating the look of the website. Most don't use backgrounds anymore. I wanted to "see" one of your products or maybe someone using it next to a passenger who's sneezing and blowing their nose, i.e., a well chosen "splash" picture is worth a thousand words.
Hope it's helpful and good luck!
http://www.LuckyGemstones.com