Download full-text PDF Gübelin and J. I. Koivula, Photoatlas of Inclusions in submitted to the NGTC Gem Laboratory for identification. Request PDF on ResearchGate | PHOTOATLAS OF INCLUSIONS IN GEMSTONES: volume 2, by Eduard J. Gubelin and John I. Koivula. (2005) Opinio Verlag. The first volume of the Photoatlas of Inclusions in Gemstones is a landmark work that Gems & Gemology In Review: Colored Diamonds PDF, The Fred Ward.
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Photoatlas of Inclusions in Gemstones visual record with accompanying descriptions of a wide variety of mineral and fluid inclusions in gems. Photoatlas, Volume 2, the long-anticipated successor to Photoatlas, Volume 1, was released in December, 2005. Like Photoatlas, Volume 1, which was first. Photo Atlas of Inclusions in Gemstones. GIA Volume 2.
Also present. From filled emeralds through beryllium-treated rubies and sapphires, the enhancement oyster is here in toto. Even the various forms of natural and man-made glass are well represented.
I was also delighted to see each major section start with an essay and a solid bibliography. This is a welcome change from previous volumes, which tended to be light on references.
Page after page of sexy strumpets strut their stuff across the paper, but the postage-stamp sized reproduction leaves both love and lust unrequited. It is my thought that, as the remaining curator of this incredible body of work, John Koivula should assemble a minimalist volume that has no pretense to education, elucidation or any other readin', 'ritin' or 'rithmetic. Instead, what I'd love to see is a full-out, large-format art book, with images chosen solely for their drama and aesthetic beauty.
Perhaps something along the lines of Steve McCurry's South Southeast where each of the 70 plates is a full 15 x 11" , along with understated captions opposite that allow the reader to simply rejoice in the beauty of nature. After all, as the authors have stated: "Nature is the ultimate expression of who we are, what we are, and where we came from. Inclusions in Sapphires From the banal to the bizarre, the latest Photoatlas covers the entire gemological waterfront, as this scene from a heat-treated Montana sapphire shows.
Inclusions in Fluorite Volume 3 of the Photoatlas also covers the inclusions of less popular gems, such as fluorite. Image stacking is commonly used today to increase the depth-of-field for a medium that has extreme limits due to the high magnification. Like all photography, the most important element is the person behind the lens and their vision to show us something in a way we've never seen it before. What separates experts from amateurs is not the equipment they use, but the manner in which they use it.
John Koivula can produce superb photomicrographs from even a primitive system because he is an artist and can paint in a variety of mediums of various resolutlions. This is what separates fine art from idle scribbling.
John Koivula is a master artist, and also a master scientist. This rare combination of sensitivtiy to both art and science have made John's work transcend each genre, expanding the interest in these tiny windows on the birth of our planet and life itself. Click on the image for a larger view.
Historical articles on inclusions in gems and crystals. The Chantaburi area has been covered by Quaternary basalts dated at 0. The basalts are generally strongly alkaline, with a low silica and high titanium content.
They are fine-grained, olivine-bearing, and occasionally contain clinopyroxene and chromium-rich spinel megacrysts with mantle-derived spinel lherzolite xenoliths. The garnets are found in the residual soils of the in-situ mass-scale weathering of the basalts.
The Trat Province is characterized by sedimentary and metamorphic rocks of Permian-Carboniferous age including siltstone, mudstone, tuffaceous sandstone, agglomerate, and locally interbedded conglomerate lenses. These rocks are overlain by basalts classified as nephelinite and olivine nephelinite of Triassic age, which are the source rocks of the studied garnets.
The investigated areas are underlain by Precambrian metamorphic complexes of amphibolites facies or anatexitic aureole with relics of Precambrian paragneisses. The rocks consist of anatexite or migmatite, augen gneiss, marble, calc-silicate rocks and quartz-mica schist [ 22 — 26 ]. Sample preparation The samples were initially investigated under optical light microscope, environmental scanning electron microscope ESEM and scanning electron microscope SEM.
For optical microscopy the samples were cut and polished in two-faced sections.
For ESEM analysis garnets were embedded in epoxy and polished. To characterize the galleries of tunnels in the garnets synchrotron-radiation X-ray tomographic microscopy SRXTM was used.
To detect and characterize organic compounds in the tunnels time-of-flight secondary ion mass spectrometry ToF-SIMS was used.
A stereozoom microscope up to 75-X magnification coupled with several illumination techniques was used to study the garnets. The acceleration voltage was 20 or 15 kV depending on the nature of the sample. The instrument was calibrated with a cobalt standard. The garnets were gold-coated before the SEM analyses. X-ray energies employed varied from 15 to 35 keV, allowing for optimal penetration. Reconstruction was performed on a Linux PC farm using highly optimized routines based on the Fourier Transform method [ 27 , 28 ].
Lenses used were x10 and x20, resulting in a voxel size of 0. They were kept in aluminium foil, treated with stainless steel forceps and cracked under sterile conditions to avoid contamination. The garnets were split in a laminar flow hood right before analyses using a cleaned chisel heptane, acetone and ethanol in that order. They were then mounted with clean tweezers on double-sticky tape on a silica wafer.
As negative controls, other minerals quartz and hematite collected in the same samples as the garnets, were analysed with ToF-SIMS. Analyses were performed both on the outside surfaces of the minerals and newly exposed surfaces split with a clean chisel. As a control, additional spectra were also acquired from the tape to confirm that samples had not been contaminated by the tape.