Pink Beryl and Emerald Crystals

Emerald is actually a member of the beryl family of gemstones (including aquamarine, heliodor, red beryl, and others), but with a higher number of impurities (known as inclusions), and colored various shades of green by trace amounts of chromium.

While dozens of questionable cures and wards for the plague are known, the royalty of both Europe and Byzantium believed that crushed emerald was the surest ward, and would save them from any plague-related death. This belief went so far as to lead the apothecaries and physicians of sixteenth-century England to release a declaration stating that the inefficacy of gems in both curing and warding the plague was due to improper identification and preparation of gems prescribed, not because the “cure” was simply a ploy on the nobility’s belief that the more expensive something was, the better it was.

A Book of Precious Stones. Julius Wodiska, 1909.

This totally fits on the blog because of the phytoplankton are ancient (just go with it ;D), and it’s way too weird to think about all of those blackboards in elementary school, smeared with the shells constructed by eons-gone eukaryotic life…crazy stuff.

rhamphotheca:

A Single Coccolithophore Cell

Billions of ancient, long-dead coccolithophores — marine phytoplankton that construct shells around themselves out of calcium carbonate scales — form the chalk that teachers use to write on blackboards.

Read this wonderful blog post from NPR’s Robert Krulwich about these amazing, microscopic organisms and their history.

http://www.npr.org/blogs/krulwich/2012/07/12/156629934/thinking-too-much-about-chalk

(Photo Credit: Alison R. Taylor, PLoS Biology, Wikimedia Commons)

(via: Smithsonian Ocean Portal)

Malachite and Azurite

You know how copper turns green when it’s left to oxidize? That process is what makes malachite green. It’s known as a copper carbonate hydroxide mineral, and is the source of most green paint pigments used until about 1800.

The rich blue mineral azurite (also one source of ancient paint pigments) is commonly found with malachite, and both are commonly found around large limestone deposits. Limestone is a form of aggregated calcium carbonate, and one of the primary sources of carbonate for both malachite and azurite formations. Arizona is the primary site where one can find malachite in North America. Malachite is more common than azurite, because it is far more stable to open air and sunlight.

Minerals from Earth and Sky, Part II: Gems and Gem Minerals. William F. Foshag, 1929.

Pink Beryl and Emerald Crystals

Emerald is actually a member of the beryl family of gemstones (including aquamarine, heliodor, red beryl, and others), but with a higher number of impurities (known as inclusions), and colored various shades of green by trace amounts of chromium.

While dozens of questionable cures and wards for the plague are known, the royalty of both Europe and Byzantium believed that crushed emerald was the surest ward, and would save them from any plague-related death. This belief went so far as to lead the apothecaries and physicians of sixteenth-century England to release a declaration stating that the inefficacy of gems in both curing and warding the plague was due to improper identification and preparation of gems prescribed, not because the “cure” was simply a ploy on the nobility’s belief that the more expensive something was, the better it was.

A Book of Precious Stones. Julius Wodiska, 1909.

Skeleton of the Ibis

Essay on the Theory of the Earth. Georges Cuvier, 1827.