ruby, treatments.6, gems

Description of rubies treated by filling surface cavities with glass.

corundum, history.1, treatments.6, gems, Arabic mineralogy, Indian lapidary

In this sweeping and richly illustrated history, S. Frederick Starr tells the fascinating but largely unknown story of Central Asias medieval enlightenment through the eventful lives and astonishing accomplishments of its greatest minds--remarkable figures who built a bridge to the modern world. Because nearly all of these figures wrote in Arabic, they were long assumed to have been Arabs. In fact, they were from Central Asia--drawn from the Persianate and Turkic peoples of a region that today extends from Kazakhstan southward through Afghanistan, and from the easternmost province of Iran through Xinjiang, China. Lost Enlightenment recounts how, between the years 800 and 1200, Central Asia led the world in trade and economic development, the size and sophistication of its cities, the refinement of its arts, and, above all, in the advancement of knowledge in many fields. Central Asians achieved signal breakthroughs in astronomy, mathematics, geology, medicine, chemistry, music, social science, philosophy, and theology, among other subjects. They gave algebra its name, calculated the earths diameter with unprecedented precision, wrote the books that later defined European medicine, and penned some of the worlds greatest poetry. One scholar, working in Afghanistan, even predicted the existence of North and South America--five centuries before Columbus. Rarely in history has a more impressive group of polymaths appeared at one place and time. No wonder that their writings influenced European culture from the time of St. Thomas Aquinas down to the scientific revolution, and had a similarly deep impact in India and much of Asia. This is a must-read for all those interested in the history of science.

gems, corundum, treatments.6, Australia.12

The late Geoff Tombs was always interested in heat treatment, publishing several papers on the subject (Tombs 1978, 1979, 1991). However the paper that sticks in my mind the most was written in 1974 and titled ‘Synthetic-like fluorescence in a natural sapphire’ Tombs 1974. At the time of writing I suspect Geoff While describing a Fine blue Ceylon sapphire submitted for testing………., Geoff was surprised by the results he obtained when examining the stone under UV light, summing up his report: Microscopic examination proved the stone to be natural. This stone is particularly interesting as it is the first naturai sapphire I have examined in which blue sections showed fluorescence characteristics exactly the same as those exhibited by the typical Verneuil synthetic blue corundum. The fluorescing areas (under S/W) were curious in that they did not follow the blue colour zoning. (Tombs 1974). In hindsight I believe Geoff was examining a heat-treated Ceylon blue sapphire a few years before such a treatment became generally known amongst the gemmological community. Most importantly, he recognised that here was something different enough to be worth reporting in his favourite magazine, The Australian Gemmologist. I dedicate this paper to him. I would like you to join me in tracing the lives and interests of several people associated with Australian sapphire. They come from widely differing backgrounds and cultures. Some are university educated, while some never went to school. Some are even still alive today. It is through their fascinating testimonies that I have been able to put this story together.

corundum, color.4, quality.10, gems, jade, color, color science, color theory

Outstanding survey of various aspects of color. Each two-page spread examines a different aspect of color. This book cannot be recommended highly enough.

gems, gem trade in Asia, gem business, trade between Europe and Asia, corundum, history.1, Early Modern trade, Armenia, Armenians, Iran, Myanmar, Sri Lanka, India, Turkey

A rare 1688 probate inventory documents the extensive gem collection of Gregorio di Girach-Mirman (1612–1688), a prominent Armenian merchant active in Venice and Livorno, Italy. Originally written in Armenian and later translated into Italian, this archival record lists more than 100,000 gemstones, including diamonds, sapphires, emeralds, and pearls, as well as more than 1,700 kilograms of rough amber, garnet, lapis lazuli, and turquoise. Housed in the State Archives of Venice, the inventory offers a uniquely detailed window into the early modern luxury trade and highlights the global commercial reach of Armenian merchant families like the Girach-Mirmans. Drawing on this previously unstudied source, along with a broader set of archival documents from across Europe and Armenia, the present article reconstructs the world of seventeenth-century gem dealing and collecting. It argues that Armenian merchants were central figures in the global trade of luxury goods, operating alongside and sometimes in competition with better-known European contemporaries. The provenance and diversity of Gregorio’s gem holdings, likely sourced from as far as modern-day Colombia, Sri Lanka, Iran, and Myanmar, attest to the geographic reach of Armenian trading networks and the sophistication of their market knowledge. By placing this inventory in its global and material context, the article contributes to ongoing discussions around early modern economic history, material culture, and global commodity flows across Eurasia and the New World. It demonstrates that gem inventories, often overlooked as solely bureaucratic and estate documents, can illuminate the complexity of merchant strategies, the transcontinental mobility of luxury goods, and the dynamics of status and prestige in the early modern period. Finally, one of the central aims of this article is to illuminate the inner workings of gem dealing in this period, including practices of sourcing and collecting, through a rare body of obscure commercial correspondence. These materials offer an exceptional view into a dimension of the trade that remains largely inaccessible and nearly absent from existing historiography.

gems, corundum, treatments.4, Sri Lanka.12, Madagascar.12, heat treatment, FTIR

This study examines sapphires naturally enriched in high-field-strength elements (HFSE) from metamorphic origins in Sri Lanka and Madagascar. These sapphires display distinctive chemical inhomogeneities and microscopic growth features, as well as variable FTIR spectra, often including a broad absorption band near 3300 cm–1. Some of the studied samples also show FTIR spectral characteristics and short-wave UV luminescence typically associated with heat-treated stones, although all were unheated. Our findings demonstrate that commonly used indicators—such as specific FTIR band patterns (mainly the 3309 cm–1 triplet) and chalky bluish white short-wave UV fluorescence—are not always reliable for identifying heat treatment. Accurate distinction between heated and unheated sapphires requires detailed microscopic examination combined with advanced trace-element analysis and spectroscopic techniques, including Raman micro-spectroscopy of inclusions such as zircon, goethite and diaspore.

gems, Burma, Burmee gems, pearls, pearl, melo pearl, Mergui, corundum, ruby, sapphire, Burma.12

Conference covered a wide range of topics related to Burmese gems and minerals.

gems, corundum, geology.11, Burma.12, Mogok, ruby, sapphire, spinel, peridot

Discussion of various gems found in Burma's Mogok Stone Tract.

gems, corundum, geology.11, Burma.12, Mogok, ruby, sapphire

Discussion of sapphire formation in Burma's Mogok Stone Tract.

gems, geology

This book is basically a retrospective of the writings/musings of John Saul, the noted geologist who discovered the John Saul ruby mine in Kenya. These essays touch on the great questions of Origins. The human adventure began when people first started to share complex ideas. A very early set of shared ideas provided a reasoned scheme that was both religious and scientific that would enable souls to take the Milky Way to the domain of the immortal gods. Other essays present cancer as originating when damaged tissues lose control over individual cells. Liberated cells multiply and may vary in ways that are incompatible with the functioning of multi-celled creatures, of humans in particular. Cancer first emerged during the Cambrian Explosion itself. Four essays discuss the survival of deep terrestrial impact-scars akin to those on the Moon, but far less easy to see. Such scars provide our planet's initial conditions. Fractures on the rim-zones of the scars guide plate tectonics and the deposition of minerals, and are implicated in at least one mass extinction.This book touches on little-discussed aspects of prehistory, history, the explosion of life during the late Precambrian, cancer research, and regional geology. Saul's writings and ideas represent some of the most original in the field of gemology, tying together not just the origins of gems, but the origins of human civilization itself. Highly recommended!