The google ranking is not as simple as PR + density. There is much more need to be done.
Even in the original paper of 1998, google claimed there's about 100 factors to be consider for the relevance of a page. As a lot of people said in this forum, anchor text is important. You need to have some good links to your site with the anchor text "Chinese collectible". Like in your signature, you should put "Chinese arts, Chinese collectibles" as the anchor text instead of just "Chinese arts, collectibles". That is important.
By the way, you maybe interested in exchange links with my Chinese calligraphy site.