rel="nofollow" href="#ulink_427f8ca2-2463-52e7-8f75-d8b73b6dcc24">Figure 3.6 The refractive indices for various materials across the visible r...Figure 3.7 The visible portion of the electromagnetic spectrum with Fraunhof...Figure 3.8 Incident light can refract and reflect (red rays) if the angle of...Figure 3.9 Electromagnetic spectrum labeled with representative colors. Wiki...Figure 3.10 Examples of light reflecting off different surfaces. Image from ...Figure 3.11 Additive (left) and Subtractive (middle) Color Theory Diagrams (...Figure 3.12 Light output from three sources of electromagnetic radiation. No...Figure 3.13 Example spectra of light output from different “colored” LEDs (a...Figure 3.14 The “color change effect” exhibited by a single 17.08 carat alex...Figure 3.15 Plot showing the change of diamond’s refractive index as a funct...Figure 3.16 Schematic of a prism with light refracting after passing through...Figure 3.17 This large 898 carat faceted cerussite (PbCO3) from Namibia, kno...Figure 3.18 Double refraction of lines drawn on paper as viewed through a si...Figure 3.19 Titanite is a rare gem mineral (but common mineral) that has a h...Figure 3.20 Peridot (left) and turquoise (right) are common idiochromatic ge...Figure 3.21 The Gachala Emerald (858 carats) from Colombia is an example of ...Figure 3.22 Very large calcite gem (1,865 carats) from St. Joe #2 Mine, Balm...Figure 3.23 Six‐rayed star in ruby (left) and chrysoberyl (right) from Sri L...Figure 3.24 Sunstone (left) showing strong iridescence from light scattered ...Figure 3.25 Pleochroism in a synthetic sapphire, as viewed with a polaroid‐p...Figure 3.26 Pleochroism in a tourmaline cut with the c‐axis parallel to the ...Figure 3.27 Transparent specimen of pink zoisite. Smithsonian National Museu...Figure 3.28 These sunstones from Oregon, USA, show varying degrees of transp...Figure 3.29 This piece of carved imperial jadeite from Burma (13.7 carats) s...Figure 3.30 Turquoise is a common semitranslucent to opaque gemstone. Specim...
4 Chapter 4Figure 4.1 An example of critical angles using quartz and diamond of equival...Figure 4.2 Conventional 10× loupe.Figure 4.3 Rock hammers are necessary tools for field geology and are useful...Figure 4.4 Dichroscope (right) and view through the dichroscope (left) of a ...Figure 4.5 Shortwave UV lamp (left) with peak output at ~254 nm and (right) ...Figure 4.6 A GIA refractometer. The stone sits in a holder within the small ...Figure 4.7 Binocular microscope with flexible fiber‐optic light sources.Figure 4.8 Example spectrum of emerald as viewed through a spectroscope. Wit...Figure B4.1.1 An example of cesium (Cs) and lithium (Li) chemical compositio...Figure 4.9 Spectral absorbance plot of emerald showing strong absorption in ...Figure 4.10 Infrared spectra of natural and synthetic amethyst from 3,640 to...Figure 4.11 Polarizing microscope and polarized photomicrograph of a zircon ...Figure 4.12 Binocular confocal microscope for nondestructive Raman spectrosc...Figure 4.13 Raman spectra of diamond and two common simulants. Each pattern ...
5 Chapter 5Figure 5.1 The Vallerano Diamond, found during excavations of a ~150 BCE tom...Figure 5.2 A map showing the positions of the various holdings at Kimberley ...Figure 5.3 Uncut (rough) diamond octahedron (left) and cut (polished) diamon...Figure 5.4 Thermal conductivities of some materials commonly encountered in ...Figure 5.5 Fluorescence of cut and rough diamonds under normal (left) and UV...Figure B5.1.1 Crystal structures of diamond (left) and graphite (right). Dia...Figure 5.6 Diamond’s crystal structure looking along a crystallographic axis...Figure 5.7 Classification of diamonds based on crystal chemistry. Breeding a...Figure 5.8 The basic shape of an octahedral diamond (left) and more complex ...Figure 5.9 Diamond octahedron (left) and diamond macle (right), as exhibited...Figure 5.10 Secondary shapes through increasing degrees of magmatic resorpti...Figure 5.11 An octahedral diamond like this one could have undergone some re...Figure 5.12 Yellow‐tinted diamond with resorption and stepped growth feature...Figure 5.13 This diamond grew initially as an unincluded (clean) crystal but...Figure 5.14 Yellow diamonds (left) from rough starting material to the oval ...Figure 5.15 Pink and colorless diamond octahedrons from the Argyle Mine in A...Figure 5.16 The DeYoung Red Diamond is of the finest red color and large siz...Figure 5.17 “Chameleon Diamond” that shows green coloration before heating a...Figure 5.18 The ~41 carat Dresden Green Diamond housed in the Green Vaults o...Figure 5.19 Before (left) and after (center) HPHT treatment of a Type IIa di...Figure 5.20 This figure shows a full range of colors that can be produced in...Figure 5.21 Mineral inclusions in diamonds may be removed or lightened by la...Figure B5.2.1 Photomicrographs of pyrope garnet inclusion (~0.15 mm wide) wi...Figure B5.2.2 Photographs of gem rough with mineral inclusions suitable for ...Figure B5.2.3 Sapphirine (left) and cordierite (right) solid mineral inclusi...Figure 5.22 Schematic vertical section through the Earth’s crust and part of...Figure 5.23 This Temperature–Pressure diagram highlights the relationship be...Figure 5.24 Morphology of a classical kimberlite diatreme, or pipe, with oth...Figure 5.25 The plan views (top) and vertical side views (bottom, also known...Figure 5.26 This figure shows the plan view (top) and vertical side view (bo...Figure 5.27 This figure shows a 3D cross‐section of one of the Ekati diamond...Figure 5.28 Compositional CaO vs. Cr2O3 diagram for garnet inclusions within...Figure 5.29 The Australian Argyle diamond mine, showing aerial imagery drape...Figure 5.30 Schematic cross‐section of the Argyle AK1 diamondiferous lamproi...Figure 5.31 Waste rock dumps at the Argyle diamond mine, Western Australia. ...Figure 5.32 Distribution of 16 Archean cratons (red) underlain by Precambria...Figure 5.33 Global rough diamond production by carat weight (not value) from...Figure 5.34 Global rough diamond production by carat weight (not value) from...Figure 5.35 Percentages of world diamond production by country by year in te...Figure 5.36 Distribution of clusters of diamond‐bearing kimberlite in Canada...Figure 5.37 The Diavik Diamond Mine and kimberlite cluster in Lac de Gras, N...Figure 5.38 Diamonds from Diavik Diamond Mine are found as perfect octahedra...Figure 5.39 Fancy yellow diamonds (left 46.5 ct, right 23.9 ct) with slightl...Figure 5.40 Macro diamond found in drill core (center of drill core) from th...Figure 5.41 Simplified anatomy and facet names of a round brilliant‐cut diam...Figure 5.42 This schematic of a Princess‐cut diamond has a perfectly proport...Figure 5.43 Drawings of diamonds showing light paths into and out of each of...Figure 5.44 Clarity scale for diamonds.Figure 5.45 Color grading scale for diamonds.Figure 5.46 Emerald cut (left, 2.02 carats) and marquise cut (right, 2.44 ca...Figure 5.47 Example prices in US$1,000 per carat by color according to clari...Figure 5.48 Price in US$1,000 per carat according to carat size and color. R...
6 Chapter 6Figure 6.1 The Kitaa Ruby from Greenland is possibly the largest ruby ever f...Figure 6.2 Ball and stick representation of corundum’s crystal structure, lo...Figure 6.3 Rubies from Greenland showing a tapered bipyramidal barrel shape....Figure 6.4 This large sapphire from Baffin Island, Nunavut, shows an elongat...Figure 6.5 This ruby crystal shows a rough hexagonal outline with a squat cr...Figure 6.6 Oscillatory zoned blue (left) and Padparadscha (right) sapphire c...Figure 6.7 These rubies and pink sapphires have an assortment of cuts and ra...Figure 6.8 The rough and two carved sides of the Kitaa Ruby. Original weight...Figure 6.9 The Carmen Lúcia ruby, a spectacular 23.1 carat stone from Burma,...Figure 6.10 Three deeply colored sapphires from the Beluga Occurrence, Baffi...Figure 6.11 Rutile fibers (also known as “silk”) in a faceted blue sapphire ...Figure 6.12 These two yellow sapphires from the Beluga Occurrence, Baffin Is...Figure 6.13 Black star sapphire showing typical asterism as a result of orie...Figure 6.14 Reeves Star Ruby (left, 138.7 carats, from Sri Lanka) and star s...Figure 6.15 Two views of an irregularly zoned sapphire from Baffin Island, N...Figure 6.16 This photo shows a blue‐violet example of the cornflower plant t...Figure 6.17 An example parcel of “before” (left) and “after” (right) heat tr...Figure 6.18 Pressure–temperature ranges for various global metamorphic gem c...Figure 6.19 Example of sapphire‐bearing marble in outcrop, Baffin Island, Ca...Figure 6.20 Marble‐hosted “gemmy” pink sapphire crystal from British Columbi...Figure 6.21 Trace element chemistry of ruby and pink sapphire from selected ...Figure 6.22 Basaltic fields of Central and East Asia through to Australia of...Figure 6.23 Simplified genetic model for alkali basalt‐hosted corundum. Coru...Figure 6.24 Xenocrystic corundum examples from Cenozoic‐aged alkali basalts ...Figure 6.25 These sapphires originated from Yogo Gulch and range in size fro...Figure 6.26 Alluvial sapphires and red corundum from Australia. (a) View of ...Figure 6.27 Photograph