David Rickard – författare

Framboids may be the most astonishing and abundant natural features you've never heard of. These microscopic spherules of golden pyrite consist of thousands of even smaller microcrystals, often arranged in stunning geometric arrays. They are rarely more than twenty micrometers across, and often look like miniscule raspberries under the microscope. The formation of a framboid is the result of self-assembly of pyrite micro- and nano-crystals under the influence of surface forces. They can be found all around us in rocks of all ages and present-day sediments, soils, and natural waters. Our planet makes billions every second and has been doing so for most of recorded geologic time. As a result, there are more framboids on our planet than there are sand grains on Earth or stars in the observable universe. The microscopic size of framboids belies their importance to contemporary science. They help us better understand inorganic self-assembly and self-organization, and studying them illuminates Earth's evolutionary history. In this book, David Rickard explains what framboids are, how they are formed, and what we can learn from them. The book's thirteen chapters trace everything from their basic attributes and mineralogy to their biogeochemistry and paleoenvironmental significance. Rickard expands on the most updated research and recent developments in geology, chemistry, biology, materials science, biogeochemistry, mineralogy, and crystallography, making this a must-have guide for researchers.

Most people have heard of pyrite, the brassy yellow mineral commonly known as fool's gold. But despite being the most common sulfide on the earth's surface, pyrite's bright crystals have attracted a noteworthy amount of attention from many different cultures, and its nearly identical visual appearance to gold has led to tales of fraud, trickery, and claims of alchemy. Pyrite occupies a unique place in human history: it became an integral part of mining lore in America during the 19th century, and it has a presence in ancient Sumerian texts, Greek philosophy, and medieval poetry, becoming a symbol for anything overvalued. In Pyrite, geochemist and author David Rickard blends basic science and historical narrative to describe the many unique ways pyrite makes appearances in our world. He follows pyrite back through the medieval alchemists to the ancient Arab, Chinese, Indian, and Classical worlds, showing why the mineral was central to the development of these various ancient cultures. Pyrite can be tracked to the beginnings of humankind, and Rickard reveals how it contributed to the origins of our art and storytelling and even to our biologic development as humans. But pyrite has unique scientific properties as well: the book distills how oxidation makes fool's gold look like a precious metal, and shows how pyrite can choke out oxygen from water, creating large "dead zones " in our oceans. Rickard analyzes pyrite's role in manufacturing sulfuric acid, a compound used for everything from cleaning drains to fertilizing crops. Its influence extends from human evolution and the formation of societies, through science and industry, to our understanding of ancient, modern, and future earth environments. Energetic and accessible, Pyrite is the first book to show readers the history and science of one of the world's most fascinating minerals.