A reference guide to gems, semi-precious stones and crystals.
Gemstones and crystals are used for jewelry, industry, lasers and precision technology. Firefly Guide to Gems is a practical, compact guide to the identification and use of precious and semi-precious stones, novelty stones, agates and crystals.
An introduction explains geology, chemistry and gemstone properties in clear and accessible terms. Key aspects of gemstones are explained such as crystal structures and optical and physical properties.
The first section of the book focuses on precious gems in their many forms, with illustrations of priceless jewelry. Practical information includes:
- Fashioning and cutting
- Types and shapes of cut
- Handling and storing gemstones
- Weighing and measuring stones
The second and main section supplies complete descriptions of a wide range of gems, organized by chemical composition, for instance:
- Carbon (diamond)
- Aluminum oxide (saphire and ruby)
- Phosphate (turquoise)
- Silica (opal)
A fascinating profile of each gem is accompanied with color photographs of the raw crystal, common cuts, and finally polished for use in jewelry. At-a-glance charts provide technical details such as refractive index, crystal group, luster, hardness and cleavage for each gem.
Easy-to-read and abundantly illustrated, Firefly Guide to Gems is ideal for collectors and rockhounds.
"Compulsivo, convincente y autoritario. Una importante adici n a nuestro entendimiento de aniguas cat strofes y su impacto en la consciencia humana. Esencial lectura para el prehitoriador altrnativo."
ANDREW COLLINS, autor de Gateway to Atlantis and From the Ashes of Angels (La Entrada a la Atl ntida y De las Cenizas de los ngeles)
Matthew Fox, autor de Original Blessing (Bendici n Original) En Catastrofobia, Barbara Hand Clow, autora de libros de gran xito, examina legendarios cataclismos y muestra como, contrario a muchas profec as de fatalidades, de hecho estamos en la c spide de una era de incre ble crecimiento creativo. El reciente descubrimiento de los vestigios de arcaicos pueblos enterrados bajo el Mar Negro, es la m s ltima instancia de evidencia en ascenso de que muchas de "miticas" cat strofes de la historia--la ca da de la Atl ntida, el Diluvio B blico--fueron eventos reales. Barbara Hand Clow muestra que una serie de desatres catacl smicos, causados por una masiva alteraci n en la corteza terrestre de hace 11,500 a os, estremeci al mundo y dej la psique humana colectiva profundamente cicatrizada. Somos una especie herida y este miedo sin procesar, que pas de generaci n, es responsable de nuestreas constantes expectativas de la apocalipsis, del Y2K al famoso final del calendario Maya en el 2012. Catastrofobia revela las insidiosas fuerzas globales, que han usado estos miedos colectivos para controlar a la humanidad por miles de a os. Pero estamos a la mitad de un tremendo cambio en el ciclo precesional de la Tierra de 26,000 a os y existe toda la indicaci n de que los cambios en la consciencia durante los ltimos treinta a os son los comienzos de una colectiva curaci n de estos profundos miedos, presagiando que un tiempo de extraordinaria actividad creativa est al alcance de la mano.
In 1793, a canal digger named William Smith made a startling discovery. He found that by tracing the placement of fossils, which he uncovered in his excavations, one could follow layers of rocks as they dipped and rose and fell -- clear across England and, indeed, clear across the world -- making it possible, for the first time ever, to draw a chart of the hidden underside of the earth. Determined to expose what he realized was the landscape's secret fourth dimension, Smith spent twenty-two years piecing together the fragments of this unseen universe to create an epochal and remarkably beautiful hand-painted map. But instead of receiving accolades and honors, he ended up in debtors' prison, the victim of plagiarism, and virtually homeless for ten years more. Finally, in 1831, this quiet genius -- now known as the father of modern geology -- received the Geological Society of London's highest award and King William IV offered him a lifetime pension.
The Map That Changed the World is a very human tale of endurance and achievement, of one man's dedication in the face of ruin. With a keen eye and thoughtful detail, Simon Winchester unfolds the poignant sacrifice behind this world-changing discovery.
America has more than 250,000 rivers, coursing over more than 3 million miles, connecting the disparate regions of the United States. On a map they can look like the veins, arteries, and capillaries of a continent-wide circulatory system, and in a way they are. Over the course of this nation's history rivers have served as integral trade routes, borders, passageways, sewers, and sinks. Over the years, based on our shifting needs and values, we have harnessed their power with waterwheels and dams, straightened them for ships, drained them with irrigation canals, set them on fire, and even attempted to restore them.
In this fresh and powerful work of environmental history, Martin Doyle tells the epic story of America and its rivers, from the U.S. Constitution's roots in interstate river navigation, the origins of the Army Corps of Engineers, the discovery of gold in 1848, and the construction of the Hoover Dam and the TVA during the New Deal, to the failure of the levees in Hurricane Katrina and the water wars in the west. Along the way, he explores how rivers have often been the source of arguments at the heart of the American experiment--over federalism, sovereignty and property rights, taxation, regulation, conservation, and development.
Through his encounters with experts all over the country--a Mississippi River tugboat captain, an Erie Canal lock operator, a dendrochronologist who can predict the future based on the story trees tell about the past, a western rancher fighting for water rights--Doyle reveals the central role rivers have played in American history--and how vital they are to its future.
An unlikely world history from the bestselling author of Cod and The Basque History of the WorldIn his fifth work of nonfiction, Mark Kurlansky turns his attention to a common household item with a long and intriguing history: salt. The only rock we eat, salt has shaped civilization from the very beginning, and its story is a glittering, often surprising part of the history of humankind. A substance so valuable it served as currency, salt has influenced the establishment of trade routes and cities, provoked and financed wars, secured empires, and inspired revolutions. Populated by colorful characters and filled with an unending series of fascinating details, Salt is a supremely entertaining, multi-layered masterpiece.
Get this popular guide and start identifying all of those rocks seen on the beaches of the north shore of Lake Superior. Included are color illustrations of each type of rock, a description, tips for recognizing it and where to go to find it.
When a perfect mineral crystal has been cut and polished into a form of great beauty by a skilled craftsperson, it is called a gem. Gems are among the most charismatic objects in the history of the world, and are probably more valuable per volume than any other artifacts from or on the earth. In this book, Dr. Jeffrey E. Post, curator of the National Gem and Mineral Collection, surveys the world of gems, discussing diamonds, corundum gems (rubies and sapphires), beryl gems (such as emeralds), quartz gems, garnets, topaz, tourmaline, peridots, zircons, spinels, chrysoberyl, spodumene, tanzanite, feldspar gems, opals, starts and cat's eyes, ornamental stones (such as jade, lapis lazuli, and turquoise), and rare and unusual gems, as well as the collection's historical jewels. Chip Clark, the museum's senior staff photographer, captures the colours and brilliance of hundreds of gems.
The Perfect Guide to Rocks and Minerals Across the United States
Keep this tabbed booklet close at hand on your next rock-hunting adventure. Based on Dan R. Lynch and Bob Lynch's best-selling field guides and featuring 56 of the most common and desirable rocks and minerals, the booklet is organized by rocks/minerals and then by general appearance for quick and easy identification. Narrow your choices by appearance, and view just a few specimens at a time. The easy-to-use format means you'll quickly find what you need to know. Plus, the quick guide is much easier to use than laminated foldouts, and the tear-resistant pages help to make the book durable in the field.
Your Must-Have Guide to Minnesota's Rocks and Minerals
Get the perfect guide to rocks and minerals in the Land of 10,000 Lakes This book by Dan R. Lynch and Bob Lynch features comprehensive entries for 90 Minnesota rocks and minerals, from common rocks to rare finds. Learn from the fascinating information about everything from agates and iron ore to fossils and gold. The easy-to-use format means you'll quickly find what you need to know and where to look. The authors' incredible, sharp, full-color photographs depict the detail needed for identification--no need to guess from line drawings.
With this field guide in hand, identifying and collecting is fun and informative.
In this brilliant exploration of our cosmic environment, the renowned particle physicist and New York Times bestselling author of Warped Passages and Knocking on Heaven's Door uses her research into dark matter to illuminate the startling connections between the furthest reaches of space and life here on Earth.
Sixty-six million years ago, an object the size of a city descended from space to crash into Earth, creating a devastating cataclysm that killed off the dinosaurs, along with three-quarters of the other species on the planet. What was its origin? In Dark Matter and the Dinosaurs, Lisa Randall proposes it was a comet that was dislodged from its orbit as the Solar System passed through a disk of dark matter embedded in the Milky Way. In a sense, it might have been dark matter that killed the dinosaurs.
Working through the background and consequences of this proposal, Randall shares with us the latest findings--established and speculative--regarding the nature and role of dark matter and the origin of the Universe, our galaxy, our Solar System, and life, along with the process by which scientists explore new concepts. In Dark Matter and the Dinosaurs, Randall tells a breathtaking story that weaves together the cosmos' history and our own, illuminating the deep relationships that are critical to our world and the astonishing beauty inherent in the most familiar things.