In the second paragraph it says: "For instance, one emerald mine established in 1981 in Santa Terezinha, Brazil, produced a peak of 25 tons of rough stones valued at $9 million in 1988; the same tonnage of stones mined in 2000 sold for only $898,000." If I took that sentence seriously, I would have to infer that the price dropped by an order of magnitude, presumably because other productive mines had been opened. But the preceding sentences says the contrary: "Thus high-quality gems can be mined out much faster than they are produced, essentially making them a finite resource." "The same tonnage" must be wrong. Please clarify.
posted by Joseph Fineman
February 20, 2012 @ 11:16 AM
In response to your question, the sentence means that the same weight in stones that were mined dropped in quality over the years, so was much less valuable by the last year cited.
posted by Fenella Saunders
February 20, 2012 @ 11:56 AM
JSTOR, the online academic archive, now contains complete back issues of American Scientist from its inception in 1913 (as Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.
A free daily summary of the latest news in scientific research. Each story is summarized concisely and linked directly to the original source for further reading.
An early peek at each new issue, with descriptions of feature articles, columns,
and more. Every other issue contains links to everything in the latest issue's table of contents.
News of book reviews published in
and around the web, as well as other noteworthy happenings in the world of science books.
To sign up for automatic emails of the
Update and Scientists' Nightstand issues, create an
online profile, then sign up in the
My AmSci area.