If it's a name for a website, I believe "ceramic nature" would do, since it's a name, and usually you don't translate names (eg. McDonalds, Coca-Cola, Sony, etc.). The only exception is that they are transliterated in different alphabets or characters. I would recommend keeping the original name, and listing the name in katakanas next to the original like I did above.

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Note added at 16 hrs (2009-12-30 05:51:40 GMT)
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I wouldn't exactly know the nature by analogy with human nature, but according to Wikipedia, I got the following relationship between humans and the beginning of ceramics.

The earliest ceramics were pottery objects made from clay, either by itself or mixed with other materials. Ceramics now include domestic, industrial and building products and art objects.

http://en.wikipedia.org/wiki/Ceramic

Also, in Japanese, the following sentence:

古くは土器に始まる。日本においては、縄文式土器、弥生式土器に始まり、時代を経て陶器・磁器へと発展し、近年では、光触媒機能をもったセラミックス繊維も開発されている。

I'm not sure if ceramic nature is related to human nature, but at least from the above, we understand that the humans have been related to ceramics from the ancient times and still do in different forms.