corundum, geology.11, gems

corundum, geology.11, gems, jade, jadeite, fei cui jade, Burma

corundum, Nepal.12, gems

corundum, quality.10, gems, color science

Two years in development, this new color communication system, based on Munsell has over 1,400 colors in this master comparison book of colors. Each of 40 pages has its own unique overlay chart, developed by color specialists and adapted for use in the jewelry industry by our own team of experts. The transparent overlay chart gives the name of the color. Highly recommended.

corundum, History.1, Geology.11, gems

During a varied career in geology, I have observed two matters that seem to stand out as fundamental truths. First of all, there is a great deal that we do not understand about the workings of the Earth. But even so, it is clear that everything is connected, not just the many aspects of geology itself — mineralogy, earthquake studies, exploration for oil and gas, and much else — but also astronomy, biology, and even cancer studies and the emergence of complex societies. e connections are not immediately evident in our usual interactions with the world around us, however, or even by plunging into specialized studies, because so many key events took place in the exceedingly distant past, and so much has changed since. Geology, along with astronomy, turns out to be a good base from which to explore the great nexus of “things connected” because its subject matter includes events that set the stage for much of what was to come. Chapter 1 of A Geologist Speculates deals with the formation of certain transparent gemstones, garnet, ruby, tourmaline, and tanzanite, among them. e elusive conditions that allowed humdrum materials to crystallize in a transparent “gemmy” manner have puzzled scientists at least as far back as the times of Robert Boyle (1627–1691). Hints how such exceptional crystals were able to form include the presence of gases with an “organic” odor associated with many gemstone deposits, their common association with graphite, and the rough alignment of many gemstone occurrences more or less parallel to modern and ancient coastlines. ere is a logical sequence and progression to the chapters, although they can be read separately. Chapters 1 and 4 require somewhat more background than others. Chapter 2 treats the origin of gas and oil. Oil companies and their exploration teams certainly appear to have done a good job in keeping the world supplied with energy. Is it possible that they have got the science wrong? Some have thought so, including Sir Robert Robinson, Nobel Laureate in chemistry in 1947, who argued that petroleum was a material of inorganic, “mineral” origin to which molecules of biological origin had been added. Robinson wrote of the “duplex origin of petroleum,” and it is likely that he was correct, unless the origin was actually “triplex” or “multiplex.” For, as suggested by their widespread occurrence throughout the Solar System and beyond, hydrocarbons are easy to make. Earthquakes, volcanism, and the world’s reserves of petroleum, and also of water, are all addressed in this chapter. In Chapter 3, I commence with the scienti c argument that the Earth and Moon are neighbors in space and that our planet could not have escaped the great bombardment that scarred the Moon early in the history of the Solar System, leaving the lunar surface saturated with impact scars. ese days it is almost universally believed that traces of this bombardment have been eliminated from the surface of our own planet by rain, wind, cycles of erosion and, most of all, by the workings of plate tectonics with the subduction and deep burial of much or the Earth’s crust. I argue di erently, claiming that the impact scars remain but that scientists have not established the correct criteria for recognizing them. Parts of my argument, which continues into Chapter 4, hinge on the geological occurrences of various transparent gemstones and the locations of certain regions rich in oil and gas. Much of Chapter 4 deals with the first appearance of large complex animals, what is commonly referred to as the “Cambrian Explosion.” is event, or, rather, this episode in the Earth’s history, was also marked by the rst formation of particular types of gemstone deposits. Excluding special cases treated in Chapter 1, no deposits of garnet, ruby, tourma-line, tanzanite, and numerous other types of transparent gemstones were formed before the approximate time of the Cambrian Explosion. In short, I argue that exceptional moun-tains — including a “supermountain” — were formed around this time, that deposits of gemstones were formed in their root-zones, and that the existence of complex animals is due to the erosion of these mountains and the materials that were then washed into the seas. For many, however, the main interest of Chapter 4 is the examination of the nature of cancer, a pathology that did not, and could not, exist before the “Explosion.” In brief, I argue that the supermountain, the gemstone deposits, the complex animals who are our ancestors, and cancer all came into existence during the same broad interval of geological time, that all were consequences of the workings of plate tectonics, and that the workings of plate tecton-ics were conditioned and guided by 3-D scars le by the same bombardment that marked the Moon. In Chapter 4, I evoked Darwinism and the workings of evolution, and in my short nal Chapter 5, I consider three life-forms that might arguably have escaped the workings of Darwinism. One case is that of human beings. I show that Darwinism is indeed universal, but I also accept that humans are somehow di erent from all other creatures, as is almost universally accepted. Darwin did not have the last word. A surprising “post-Darwinian” factor came into play during the first generation of the Paleolithic when religion, purpose-ful observations of earth and heavens, and mythmaking were all inserted into the ways of humans, inserted virtually instantaneously.

gems, history of gemology, Venice, Renaissance, culture, history of jewelry, history of gems, corundum, ruby, history.1, carbuncle, balas ruby

In Private Lives in Renaissance Venice, Patricia Fortini Brown argues that material culture served as a means by “which Venetians attempted to define and defend family identity and social rank.” Her seminal study examines a wide variety of objects, including furniture, tapestries, glassware, and, of course, portraits. According to Fortini Brown, items in the latter category served as “an important emblem of an aristocratic lifestyle.” This interpretation clearly applies to Lorenzo Lotto’s Portrait of a Lady as Lucretia (fig. 11a) and Paolo Veronese’s Portrait of Jacob König (fig. 11b). However, the two portraits share more than the early modern goal of defining an elite public identity. Rather, jewelry and gems figure prominently in both images. As is common in such portraits, the combination of gem and gesture mediates between viewer and object. In both portraits, the sitter draws the viewer’s attention to a precious object. Lucretia’s upturned palm and fingers point to a beautiful jeweled pendant that spills down over her corseted bodice, while König leans toward the viewer to display the massive emerald in his right hand. Yet a fundamental difference exists in the objects of display in these two images. The gems in Lucretia’s pendant play a supporting role as part of a larger gold setting. In Veronese’s portrait of König, the emphasis remains squarely on the emerald. While it might be tempting to attribute these representational decisions solely to the necessities of gender conventions, a larger issue informs this comparison. As will be demonstrated, in the sixteenth century jewelry featuring elaborate decorative settings such as Lucretia’s pendant would come to be matched by a newfound fascination with the natural stone itself.

gems, jade, Mughal jade carving nephrite, China, beryl, emerald, spinel, ruby, gold jewelry, Indian lapidary

Throughout its history, India has produced countless types of jewelry as a huge country with an almost unmanageable number of peoples and tribes. The precious ones were not only intended to decorate or provide information about the social rank of the wearer, they also served as magical protection and were indispensable in some religious ceremonies. Many pieces of jewelry also had a symbolic meaning and can be associated with ancient Indian myths due to their materiality. The publication ranges from magnificent pieces from princely treasuries to precious jade objects to the highly elaborately decorated jewelry of the Rabari people with gold granules.

corundum, Madagascar.12, gems

In May 2012, the GRS lab in Bangkok received two very large, high-quality rough ruby crystals (Fig. 1A) for testing from a client who had own straight to the lab from Madagascar.The concerned client had heard rumors swirling about in Madagascar that the crystals were synthetic, and that he needed confirmation of their authenticity before his group would proceed with further investments.Laboratory testing with ED-XRF, FTIR, UV-VIS, Raman and microscope of the specimens confirmed that the huge crystals were indeed natural and unheated. To link these crystals to the mine in question for their client, the authors undertook a perilous field trip to the source of the crystals for a first-hand inspection of the mine site. By documenting the gemstone rush on video and collecting rock and mineral samples from the site for comparison, they would be able to decode the geological conditions under which this corundum deposit was formed.

corundum, quality.10, gems

corundum, quality.10, Ruspoli sapphire, gems