Book and Media Reviews pubs.acs.org/crystal
Review of El Misterio de Los Cristales Gigantes (The Mystery of the Giant Crystals) Changing continents, we visit the world’s largest subterranean mine in Chile, El Teniente, located at the western flank of the Andes mountains. In addition to being the site of an abandoned modern mining town, now a national monument, the Caverna de los Cristales harbors some of the largest gypsum crystals known to date. Growing on a base of golden pyrite crystals and baryte, these perfectly transparent crystals measure more than 25 ft in length and harbor in their mother liquor inclusions the secrets to their unique growth conditions. But, alas, even that discovery can be topped. Back at the Naica mine in the Chihuahua desert of Mexico, 950 ft below ground, the Cueva del los Cristales harbors the most miraculous and beautiful gypsum crystal giants ever discovered. Protected in a hot and humid environment, these giants extend from bare rock faces across the entire cave. Measuring more than 30 ft in length and 3 ft in diameter, the columns dwarf the ant-like researchers navigating the cave. How could these huge crystals have formed? Experiments in the laboratory reveal that these gypsum crystals grew hydrothermally over a period of 500,000 years from calcium sulfate solutions originating from anhydrite (waterless calcium sulfate) deposits that were dissolved and slowly redeposited as gypsum crystals by the hot, subterranean water sources filling the cavities in the volcanic bed rock. All in all, this DVD is a great educational tool in the classroom and a fabulous gift to anyone who wants to spread the fascination of science and its power to explain even the greatest miracles of our universe. Highly recommended.
El Misterio de Los Cristales Gigantes (The Mystery of the Giant Crystals). Film directed by Javier Trueba. Written and presented by Juan Manuel Garcia-Ruiz. Madrid Scientific Films: Madrid, Spain, 2010. (Multizone DVD & Blu-ray). HD 16:9 format, 50 min; English, French, Spanish, and Italian narration. Distributed by Triana Science and Technology. Available from Hampton Research. US $19/$38.
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ne of the most frequent complaints voiced by frustrated educators is that kids and young students are difficult to attract to Science, Technology, Engineering, Mathematics (STEM) fields of study. Given the attraction of almost all youngsters (and not so young ones) to huge objects like construction equipment (yes, girls like Terex trucks, too), this DVD of El Misterio de Los Crystales Gigantes (The Mystery of the Giant Crystals) is the right tool for you (the DVD trailer is available at http://www.youtube.com/watch?v=jEU9ltjVwcs). Crystallographer or not, it is practically impossible not to be seriously impressed and fascinated by the almost oppressive size and beauty of the stars of this movie, the giant crystals in the Cueva de los Cristales of the Naica mine in Mexico’s Chihuahua state. The DVD is competently narrated by Juan Manuel GarciaRuiz, an accomplished crystallographer and crystal grower. Juan Manuel leads us in a well-composed journey through the history and legends of big crystals, richly endowed with images of stunning, even incredible, beauty. We start with a visit to the ancient Roman mines of Segobriga in Spain, tracing the source of its past riches the mining and export of the “crystals of Spain”: Large transparent plates of gypsum crystals (CaSO4·2H2O) were the primary window panel material before the invention of ultimately much cheaper, amorphous sodiumsilicate glass. We also learn the critical difference between a glass and a crystal the internal order that endows crystals with their beauty and regularity. We learn that the perfect cleaving of the gypsum crystals occurs along the ordered planes of weak crystal contacts mediated by water molecules which alternate with calcium sulfate layers. We proceed to visit the abandoned Mina Rica near Almeria and explore the famous geode of Pulpi, a cavity containing huge gypsum crystals of near perfect transparency looking like huge blocks of ice. We understand now how the word crystal originates from ancient Greek sources, indicating the appearance of such crystals as kryo (κρύο), similar to cold and frozen, icy water. And, most importantly, we recognize that even the so beloved smartphones of our distractedly texting students would not exist without our ability to understand and grow huge semiconductor crystals a point that should not be lost on our young disciples. During a visit to the laboratory, we also begin to understand how such miraculous crystals can form and that the process requires unique conditions and geological time scales (at this point, even the opportunity to convert an occasional creationist to accept the modern view of science might present itself). © 2012 American Chemical Society
Bernhard Rupp
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k.k.Hofkristallamt, San Marcos, California
AUTHOR INFORMATION
Notes
The authors declare no competing financial interest.
Published: February 22, 2012 1695
dx.doi.org/10.1021/cg300182h | Cryst. Growth Des. 2012, 12, 1695−1695
