Carbon trade in both types of diamonds exists, the two markets act in dramatically different ways. Unlike precious metals such as gold or platinum, gem diamonds do not trade as a commodity: there is a substantial mark-up in the sale of diamonds, and there is not a very active market for resale of diamonds. Industrial diamonds are valued mostly for their hardness and heat conductivity, with the gemological qualities of clarity and color being mostly irrelevant. About 80% of mined diamonds (equal to about 100 million carats or 20 tonnes annually) are unsuitable for use as gemstones are relegated for industrial
Purity and Danger contexts. What is regarded as dirt in a given society is any matter considered out of place. (Douglas took this lead from William James.) She attempted to clarify the differences between the sacred, the clean and the unclean in different societies and times. But this does not entail judging religions as pessimistic or optimistic in their understanding of purity or dirt—e.g., as dirt-affirming or otherwise. Through a complex and sophisticated reading of ritual, religion, and lifestyle, Douglas challenged Western ideas of pollution, making clear how the context and social history is essential. As an example of this approach, Douglas first