DOCSLIB.ORG

THE HOPE DIAMOND GRAPHENE DIAMONDS in the ROUGH Solving the Mystery

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
THE HOPE DIAMOND GRAPHENE DIAMONDS in the ROUGH Solving the Mystery ResonanceIssue 9 | Autumn 2018 The University of Sheffield’s Chemistry News Team THE HOPE DIAMOND GRAPHENE DIAMONDS IN THE ROUGH Solving the mystery. Where is it now? From jewels to drills. Contents Resonance The University of Sheffield’s On the Cover In This Issue Chemistry News Team Editorial 1 Resonance is a biannual newsletter produced by chemistry Diamonds in the Rough 3 Editor Resonance 3 Josh Nicks students at the University of Sheffield. It aims to provide insights into unheard stories from the department and Rosalind Franklin 4 Design Editor to engage its readers with issues in the wider scientific world. Josh Nicks Graphene: Where is it Now? 5-6 Elemental Factfile: Carbon 6 Social Media Coordinator Editorial Diamonds in the Rough James Shipp Favoured by both royalty and precision engineers alike, Laser Lab Opening 7-8 This is now my second issue as editor of resonance, and this issue Zoe Smallwood details why diamonds are useful beyond marks the end of my fifth year studying at the University of Sheffield. wedding rings. The Hope Diamond 9-10 Contributing Authors Throughout my time here I have been frequently exposed to stories of great accomplishments made in this department, both past and present, New Head of Department: 11-12 Josh Nicks and it is my privilege to be able to be one of the first to hear them. Interviewing Graham Leggett James Shipp Zoe Smalwood This issue is somewhat oxymoronic, in that its focus is actually Departmental News 13-15 Dave Ashworth incredibly vague when you think about it - carbon. Carbon is all Abbie Sinclair around us: in the air we breathe, the clothes we wear, the things Kitchen Chemistry: Deep-frying 16 Jasmine Catlow we eat and even our very muscles and organs. It is also fundamental 5 Crisps Mahir Mohammed to the field of chemistry, so much so that organic chemistry is based almost solely on the study of its molecular compounds. t Chemistry Crossword 17 This issue aims to bring to light some interesting stories involving carbon, Copy Editors from a supposedly cursed diamond, to a nanomaterial deemed to be the This Semester in Pictures Back solution to a cacophony of materials chemistry problems. Aside from Josh Nicks this, we have an interview with our new Head of Department, Prof. Graphene: Where is it Now? James Shipp Graham Leggett, detailing his plans for the Department’s future. Of Dr Grant Hill An article focussing on graphene’s story since it’s course, these plans are likely to include the new laser lab opened by Prof. Check Us Out Prof Anthony J. H. M. Meijer discovery in 2004, and whether or not it lived up to its Weinstein, whom Abbie Sinclair and James Shipp interviewed for details. intial hype. @resonancenews If you’re reading this with your lunch, you might find our “kitchen chemistry” section interesting, which explains the @SheffieldChem Email science behind crisp manufacture. Alternatively, if you’re more of [email protected] a history buff, you can read a short biographic article on the late @sheffield.chem Rosalind Franklin and her many academic accomplishments. 9 The University of Sheffield Before you dive in, I’d like to thank my team for this issue and all University of Sheffield Chemistry Alumni Printers the hard work they’ve put into writing the articles. Jas Catlow and Mahir Mohammed in particular have written two fantastic and Print and Design Solutions @Resonance_Sheff Bolsover Street unique articles about two topics I originally knew nothing about! Sheffield Zoe Smallwood continues to impress with her article on two S3 7NA contrasting uses of diamonds, and Dave Ashworth has applied his [email protected] research expertise in two-dimensional materials to his feature article. The Hope Diamond Modern analytical techniques preempt the solution to Once again, happy reading, a centuries-long mystery involving a diamond and its www http://bit.ly/2weV7M1 curse. Joshua Nicks 1 Resonance Issue 9 || Autumn 2018 The University of Sheffield || Resonance Issue 9 2 Feature InterviewInsight Diamonds in the Chemistry Greats: Rough Rosalind Franklin By Zoe Smallwood By Joshua Nicks ften found glistening in tiaras of the nitrogen is as important as due to the inclusion of more nitrogen n 1962, the Nobel Prize in relation to coal and related materials’ finally culminated in the proposition Oand engagement rings, diamonds the quantity; if spread throughout from their formation process, limiting Iphysiology and medicine was being completed in tandem with the of a double-helix structure with are considered a true symbol of wealth the stone, the colour is much darker their aesthetic value in an industry awarded to James Watson, Francis British Coal Utilisation Research complimentary strands. This data and opulence. Their popularity with than if they are located in clusters at which prizes colourless diamonds. Crick and Maurice Wilkins “for their Association during the second world was a vital factor in Watson and jewellers is attributed mostly to their certain sites - the type of nitrogen discoveries concerning the molecular war. It is often overlooked that her Crick’s model, which would most natural sparkle and colour (or, to inclusion can be detected using structure of nucleic acids and its proficiency in X-ray diffractometry likely not exist otherwise. This be more precise, the lack of colour - electron paramagnetic resonance significance for information transfer in techniques came as a result of her time resulted in Watson and Crick’s model completely colourless diamonds are to help validate the colour. Much living material.” However, by their own spent as a post-doctoral researcher at being published in Nature, alongside extremely valuable). However, the rarer colours are caused by other admission, Watson and Crick could the Laboratoire Central des Services two papers written by Franklin and smaller stones that don’t find their imperfections such as boron (blue), not have arrived at their model of Chimiques de l’Etat in Paris. Her Wilkins (separately) which supported way onto rings and pendants are used graphite (black) or defects in crystal DNA without X-ray crystallographic work there focused on applying it. in performance cutting tools and high growth (red). The Aurora Pyramid data obtained by one Rosalind diffractometry to imperfectly pressure cells. of Hope, currently an exhibit in the A comparison between diamond (left) Franklin. Though Franklin’s career, crystalline materials – namely coal. Franklin did not fit in well at King’s, Natural History Museum, displays and synthetic moissanite (right). and possible Nobel recognition, were The papers she published on this and chose to leave in 1951, moving Whilst these two applications may 296 natural diamonds, each a different cut short by her untimely death in research continue to be cited today, to Birkbeck College. Here she began seem completely unconnected (after colour! More recently, another form of 1958, this article aims to demonstrate and earned her a great deal of respect her work on RNA viruses, publishing all, why would a drilling tool need to be synthetic diamond has begun to just how significant her discoveries in the field. 14 papers between 1955 and 1958 sparkly?), it is the extreme hardness of appear. Moissanite, a crystalline form were to chemistry as well as science as and becoming an expert in the the stone that links the two. The word of silicon carbide, has a hardness a whole. topic. Her work ethic did not falter, ‘diamond’ is derived from the Greek only marginally less than diamond with 13 of these papers having been word ‘adamas’ which literally translates and is normally used for cutting of published after her cancer diagnosis. as ‘unbreakable’, with a hardness and precious metals in the jewel industry. Unfortunately, three others had to stability greater than any other natural Moissanite is named after Dr Henry be submitted for publication by her compound. This supreme strength is Moissan, who discovered trace students after her death in 1958. due to an “infinite” network of strong amounts of the stone in a meteor crater One of these students, Aaron Klug, carbon-carbon bonds arranged in a in the late 1800’s. The sparse amounts went on to win the 1982 Nobel Prize tetrahedral structure. formed naturally meant it was not in chemistry for his development of Photograph 51, from which Franklin until 100 years later that an industrial crystallographic electron microscopy. derived the double helix. Whilst the demands of drilling are process for manufacturing jewellery- much more intense than normal life, quality stones was developed. In 1951, Franklin moved to King’s So there you have it, Franklin was an the extreme hardness and scratch The Aurora Pyramid of Hope under Unlike diamonds, moissanite is only College London, where she worked authority in physical chemistry and resistance means that diamonds both visible and UV light. formed synthetically, making it a on DNA for two years. She worked particularly diffractometry during keep their sparkle and shine almost cheaper and less ethically concerning in the lab of John Randall, alongside her career. We cannot know whether indefinitely; a hugely desirable feature Due to cost and ethical considerations, alternative to some mined diamonds. Rosalind Franklin Wilkins - though the two did not get her death stopped her from being in jewellery. Softer minerals such as more and more consumers are A bonus is that moissanite has a on. Here, Franklin became the first awarded the Nobel Prize ahead of opals, are brightly coloured but are buying synthetic gemstones instead higher refractive index, making Franklin was born in 1920, into a well- to identify the two forms, dubbed A Wilkins. After all, sexist attitudes less common in rings, particualrly of those mined from the ground.
Load more

Recommended publications
  • The Wittelsbach-Graff and Hope Diamonds: Not Cut from the Same Rough
    THE WITTELSBACH-GRAFF AND HOPE DIAMONDS: NOT CUT FROM THE SAME ROUGH Eloïse Gaillou, Wuyi Wang, Jeffrey E. Post, John M. King, James E. Butler, Alan T. Collins, and Thomas M. Moses Two historic blue diamonds, the Hope and the Wittelsbach-Graff, appeared together for the first time at the Smithsonian Institution in 2010. Both diamonds were apparently purchased in India in the 17th century and later belonged to European royalty. In addition to the parallels in their histo- ries, their comparable color and bright, long-lasting orange-red phosphorescence have led to speculation that these two diamonds might have come from the same piece of rough. Although the diamonds are similar spectroscopically, their dislocation patterns observed with the DiamondView differ in scale and texture, and they do not show the same internal strain features. The results indicate that the two diamonds did not originate from the same crystal, though they likely experienced similar geologic histories. he earliest records of the famous Hope and Adornment (Toison d’Or de la Parure de Couleur) in Wittelsbach-Graff diamonds (figure 1) show 1749, but was stolen in 1792 during the French T them in the possession of prominent Revolution. Twenty years later, a 45.52 ct blue dia- European royal families in the mid-17th century. mond appeared for sale in London and eventually They were undoubtedly mined in India, the world’s became part of the collection of Henry Philip Hope. only commercial source of diamonds at that time. Recent computer modeling studies have established The original ancestor of the Hope diamond was that the Hope diamond was cut from the French an approximately 115 ct stone (the Tavernier Blue) Blue, presumably to disguise its identity after the that Jean-Baptiste Tavernier sold to Louis XIV of theft (Attaway, 2005; Farges et al., 2009; Sucher et France in 1668.
    [Show full text]
  • Renowned for His Iconic Designs and Breathtaking Gem Collections, Harry Winston Was a Man Who Knew the True Value of a Diamond
    A BRILLIANT LEGACY Renowned for his iconic designs and breathtaking gem collections, Harry Winston was a man who knew the true value of a diamond. BY ALLISON HATA 54 A diamond is anything but just another stone. Highly coveted, precious and exceedingly rare, diamonds can take on different meanings: a symbol of status, a statement of love or a sign of purity. “Diamonds are a physical connection to [the earth] other than our feet on the ground,” says Russell Shor, a senior industry analyst for the Gemologist Institute of America. “When the earth was young and there was volcanic mass seething inside—this is how diamonds were formed. Diamonds connect us to that.” One man understood this intrinsic connection and dedicated his life to bringing the world closer to the precious gem through his jewelry designs and generous gifts to national institu- tions. Known as the “king of dia- monds,” the late Harry Winston was the first American jeweler to own and cut some of the most iconic stones in history, in addi- tion to setting a new standard for jewelry that showcases a gem’s natural beauty. Born more than a century ago, the young Winston—the son of a small jewelry shop owner—demonstrated a natural instinct for examining diamonds and precious gems. In subsequent years, he cultivated this talent to become one of the most prominent diamond merchants and designers of his time. His legacy lives on through the house of Harry Winston, which pairs his classic vision with a contemporary sensi- bility to create modern pieces that still grace the red carpet today.
    [Show full text]
  • Christie's Presents Jewels: the Hong Kong Sale
    FOR IMMEDIATE RELEASE October 28, 2008 Contact: Kate Swan Malin +852 2978 9966 [email protected] CHRISTIE’S PRESENTS JEWELS: THE HONG KONG SALE Jewels: The Hong Kong Sale Tuesday, December 2 Christie’s Hong Kong Hong Kong – Christie’s announces the fall sale of magnificent jewellery, Jewels: The Hong Kong Sale, which will take place on December 2 at the Hong Kong Convention and Exhibition Centre. This sale features an exquisite selection of over 300 extraordinary jewels across a spectrum of taste and style, from masterpieces of the Belle Époque to contemporary creations, and from the rarest of white and coloured diamonds to important coloured stones. COLOURLESS DIAMONDS Leading the auction is a rare pair of D colour, Flawless diamonds weighing 16.11 and 16.08 carats (illustrated right, estimate: HK$40,000,000-60,000,000 / US$5,000,000-8,000,000). These marvellous stones are also graded ‘Excellent’ for polish, symmetry and cut grade, making them exceedingly rare for their superb quality. Classified as Type IIa, these diamonds are the most the chemically pure type of diamonds known, with no traces of the colorant nitrogen. The absence of this element, seen in 98% of diamonds, gives these stones a purity of colour and degree of transparency that is observed only in the finest white diamonds. The modern round brilliant cut is the diamond’s most basic and popular shape, as it allows the potential for the highest degree of light return. But more importantly, the round diamond sustains the highest value as its production requires riddance of the greatest amount of diamond rough.
    [Show full text]
  • The Red Diamond
    The Red Diamond John Fitzgerald Rob Floyd The Red Diamond Text and image copyright © John Fitzgerald and Rob Floyd 2012 Thalassa by Louis MacNeice is reproduced by kind permission of David Higham literary, film and TV agents. The authors would also like to thank Penguin Books for permission to quote from King Arthur and His Knights of the Round Table by Roger Lancelyn Green, and Colin Wilson for the phrase, ‘Imagination is the Herald of Change’. Contents Welcome The Sulphurous Heart Seekers in the Sunrise Britain is Our Playground Daughters of the Revolution The Arch of Constantine The Lantern Bearer Temenos The Mind and the World The Room of the Golden Dance Glittering Prize Rebel Angels Useful Idiots Panache, Power and Pride Visions and Ruins The God Abandons Antony The Red Diamond The Far Wall Welcome Man is in love with what abandons him. That’s the starting point of every quest. Meister Eckhart ******* Hello, thank you and welcome to The Red Diamond. We hope it stirs your imaginations and that you enjoy it in every way. The Red Diamond is essentially an Art Book, with Rob’s illustrations playing as central a role in the story’s unfolding as does my text. Our intent has not been so much to say, ‘this happened here, that happened there and here’s the picture to prove it’, but rather to allow words and pictures to come together in the hope of creating new contemplative spaces – evocative spaces – spaces of growth, possibility and playful creative change. The text tends therefore to concentrate more on atmosphere and mood than the adoption of a purely realistic approach to the story’s development.
    [Show full text]
  • Compilation of Reported Sapphire Occurrences in Montana
    Report of Investigation 23 Compilation of Reported Sapphire Occurrences in Montana Richard B. Berg 2015 Cover photo by Richard Berg. Sapphires (very pale green and colorless) concentrated by panning. The small red grains are garnets, commonly found with sapphires in western Montana, and the black sand is mainly magnetite. Compilation of Reported Sapphire Occurrences, RI 23 Compilation of Reported Sapphire Occurrences in Montana Richard B. Berg Montana Bureau of Mines and Geology MBMG Report of Investigation 23 2015 i Compilation of Reported Sapphire Occurrences, RI 23 TABLE OF CONTENTS Introduction ............................................................................................................................1 Descriptions of Occurrences ..................................................................................................7 Selected Bibliography of Articles on Montana Sapphires ................................................... 75 General Montana ............................................................................................................75 Yogo ................................................................................................................................ 75 Southwestern Montana Alluvial Deposits........................................................................ 76 Specifi cally Rock Creek sapphire district ........................................................................ 76 Specifi cally Dry Cottonwood Creek deposit and the Butte area ....................................
    [Show full text]
  • Lab 2 – Mineral Properties and Non-Silicate Minerals
    LAB 2: MINERAL PROPERTIES AND NON-SILICATE MINERALS Lab Structure Yes – review concepts from Labs 1 and 2 in preparation Recommended additional work for Test 1 Required materials Mineral ID kit, Mineral Kits 1 and 2, pencil Learning Objectives After reading this chapter, completing the exercises within it, and answering the questions at the end, you should be able to: • Describe mineral lattices and explain how they influence mineral properties. • Categorize minerals into groups based on their compositions. • Describe some of the important techniques for identifying minerals. • Identify and describe the physical properties of a range of non-silicate minerals in hand sample. • Discuss the economic uses of non-silicate minerals. Key Terms • Cation • Phosphate • Anion • Colour • Silicate • Streak • Non-silicate • Lustre • Native element • Hardness • Sulphide • Crystal habit • Oxide • Cleavage • Hydroxide • Fracture • Sulphate • Conchoidal fracture • Carbonate • Specific gravity • Halide Minerals are all around us: the graphite in your pencil, the salt on your table, the plaster on your walls, and the trace amounts of gold in your computer. Minerals can be found in a wide variety of consumer products including paper, medicine, processed foods, cosmetics, electronic devices, and many more. And of course, everything made of metal is also derived from minerals. 49 | Lab 2: Mineral Properties and Non-Silicate Minerals As defined in the introductory chapter, a mineral is a naturally occurring combination of specific elements arranged in a particular repeating three-dimensional structure (Figure I4). “Naturally occurring” implies that minerals are not artificially made. Many minerals (e.g., diamond) can be made in laboratories, but if they can also occur naturally, they still qualify as minerals.
    [Show full text]
  • Lab 2: Mineralogy
    Lab 2: Mineralogy Reading Understanding Earth, Ch. 3, and Appendix 4 Objectives • To learn how minerals are classified • To learn the common properties of mineral groups • To identify common minerals found in the Earth’s crust Introduction The crust of the Earth is made up of a variety of different rocks. Each type of rock is formed from an assemblage of minerals. Minerals are the basic "building blocks" of rocks, and the recognition of common minerals and rocks is an essential part of the study of geology. A mineral is defined as a chemical element or compound that is a naturally-occurring crystalline solid and is formed as a result of inorganic processes. The terms "rock" and "mineral" are often erroneously used interchangeably. It is important, therefore, to emphasize the key differences between these materials. A mineral is a substance formed by nucleation and growth in an “orderly, three dimensional array.” It is relatively continuous and homogeneous, with a set chemical composition or range of compositions. A rock is an aggregate of minerals with possible wide variations in chemical compositions and crystal structures. A mineral can be represented by a chemical formula, while a rock cannot. Figure 2.1 The difference between a mineral and a rock. Left: The mineral garnet. Right: The rock eclogite, made up of garnet and clinopyroxene. Although there are over 3000 minerals that have been discovered, fewer than 30 make up the bulk of the earth's crust. These are called the rock-forming minerals, and are the ones you are most likely to encounter in the rocks around you.
    [Show full text]
  • 2012 HK Christies Coloured Stones
    Christie’s Expert Lecture Sunday 27th May 2012 Colourful Treasures of Nature: Ruby, Sapphire, Emerald & Pearls presented by Dr. Michael S. Krzemnicki Swiss Gemmological Institute SSEF Photos © M.S. Krzemnicki, SSEF, except where indicated otherwise Coloured gemstones are formed during large-scale geological processes which have shaped the world as we know it today...! Foto: Baltoro-Gletscher, Karakorum; Guilhem Vellut via, WikiCommons! 1! Kashmir sapphire Foto: Baltoro-Gletscher, Karakorum; Guilhem Vellut via, WikiCommons! The collision of the Indian plate with the Eurasian continental plate has produced some of the most important sources for coloured gems, such as the sapphires from Kashmir and the sapphires and rubies from Burma, and many more.! 2! Inclusions should not only be considered as imperfections, ! but rather as individual proof and fingerprint of the age and formation conditions of a gemstone!! Garnier et al. 2006! Foto:H.A. Hänni, SSEF! © Swiss Gemmological Institute SSEF Inclusions may also be very characteristic for a specific provenance of a gemstone, thus being a valuable proof for its origin.! Blue colour zone in a ruby from Mong Hsu (Burma)! © Swiss Gemmological Institute SSEF 3! These sources for coloured stones are often known since historic times and their gems have been treasured over centuries for their beauty and rarity.! Bagan, Burma © P. Boegli, Flickr.com! © Swiss Gemmological Institute SSEF Where do the stones come from... © Swiss Gemmological Institute SSEF 4! Mwarasi'ruby'deposit,' Tanzania' © Swiss Gemmological Institute SSEF Near Mahenge, Central Tanzania: spinel & ruby mines © Swiss Gemmological Institute SSEF 5! Matombo (Uluguru Mountains)" Morogoro Province! Foto: W. Balmer, 2009! The Umba valley, Northern Tanzania © Swiss Gemmological Institute SSEF 6! The varieties of Corundum: Ruby, Sapphire, & Fancy sapphires: Trace elements resulting in a wide range of attractive colours including padparadscha © Swiss Gemmological Institute SSEF Sapphire 7! Kashmir sapphire The Kashmir sapphire mines from Tom D.
    [Show full text]
  • The Duncan to Mayco Conversion Chart
    TO CONVERSION CHART CC135 Lake Blue .......................UG72 Wedgewood Blue CC203 Neon Chartreuse ....................UG218 Pear Green CC136 Marlin Blue ...........................UG94 Pansy Purple CC204 Neon Orange......................UG85 Orange Sorbet CC137 Regency Purple.....................UG87 Regal Purple CC205 Neon Green ............................UG218 Pear Green CC140 Morocco Red .................................UG10 Crimson CC206 Neon Red .................................UG208 Fame Red AG401 Marbled Celadon ...................EL131 Turtle Shell CC141 Light Yellow .........................UG46 Bright Yellow AG402 Turquoise Haze ...................EL136 Lapis Lagoon CC142 Canary Yellow ......................UG46 Bright Yellow AG403 Ocean Mist ...............................EL103 Sea Spray CC143 Yellow Orange ..................UG203 Squash Yellow AG404 Winter Fog ...........................EL124 Stormy Blue CC144 Burnt Orange ...................UG203 Squash Yellow AG405 Smoke Stack ..........................EL101 Oyster Shell CC145 Indian Red ..................................UG31 Chocolate CN012 Bright Straw* ............................SC24 Dandelion AG406 Aged Moss .........................EL125 Sahara Sands CC146 Purple ........................................UG93 Wild Violet CN022 Bright Saffron* ..........................SC24 Dandelion AG408 Oyster Shell ................... EL140 Toasted Almond CC148 Deep Turquoise .......................UG19 Electra Blue CN052 Bright Tangerine* ...........SC50 Orange Ya Happy AG409
    [Show full text]
  • Zircon - a Very Old Gemstone 鋯鋯石 - 由來已久的寶石 Prof
    Zircon - A Very Old Gemstone 鋯鋯石 - 由來已久的寶石 Prof. Dr Henry A. Hänni（亨瑞 翰尼）, FGA, SSEF Research Associate Fig. 1 A selection of zircons of various origins. The greyish cabochon is a cat’s eye weighing 4.5 cts. 一組不同產地的鋯石。灰色調的素面鋯石貓眼為4.5 cts。 Photo © H.A.Hänni 本文提及兩種含鋯的常見寶石材料 — 鋯石和 hafnium and lead, Zircons usually contain traces 氧化鋯。作者詳述了鋯石的特徵 — 獨特的脫 of the radioactive elements uranium and thorium. 晶法，它不但影響寶石的物理特性，而且間接 As these decay, naturally, over millions of years, 地形成星光或貓眼效應；同時描述鋯石的產地 the alpha particles released gradually destroy 及顏色處理，並簡述氧化鋯的特性。 the zircon crystal lattice, a process that is called metamictisation. The degree of metamictisation Introduction depends on the concentraton of radioactive The mineral Zircon has quite a simple chemical elements and the duration of irradiation. Fig. 3 formula, ZrSiO4; a zirconium orthosilicate. shows a qualitative ED-XRF analysis, showing the Zircons are magnificent gemstones with a high elements present in a metamict green gem from lustre, and they occur in different colours, such Sri Lanka. as white, reddish, yellow, orange and green (Fig. 1). Coloured varieties of zircon may appear in the market as hyacinth (golden to red-brown), jargon (colourless to grey and smoky), metamict (green) or starlite (blue). These terms including “matara diamond” are largely obsolete and only used in older books. Zircons from Cambodia can be heated to blue or colourless. In the early 20th century heated colourless zircons were the perfect Fig. 2 A collection of rough zircons from various deposits: On substitute for diamonds. the left Mogok (Burma), on the right Tunduru (Tanzania), granite sample with zircon, Madagascar (5 cm across).
    [Show full text]
  • Mineral Properties and Identification
    UNIVERSITY of SOUTH AUSTRALIA School of Natural and Built Environments, Mawson Lakes Mineral properties and identification Text reference: Marshak, S. (2012) Earth: Portrait of a Planet. 4th edition, WW Norton & Co., Chapter 5. INTRODUCTION This practical is intended to introduce you to the physical properties of minerals and the ways in which those properties are used in the practical identification of mineral specimens. On completion of this practical, you should be able to: 1. Determine the physical properties of minerals, such as hardness, cleavage and lustre; 2. Distinguish between mineral cleavage, crystal faces and fracture surfaces, and recognise the various types of cleavage; 3. Use a mineral identification key or set of mineral identification tables to successfully identify some common rock-forming minerals. PHYSICAL PROPERTIES OF MINERALS What is a mineral? • Naturally occurring; • Solid and crystalline; • Orderly arrangement of atoms; • Definable chemical composition; • Usually inorganic. Each mineral has a unique set of physical properties that allows it to be identified. Together, two or three of these properties may be diagnostic for a given mineral. Some of the most commonly used properties are: 1. COLOUR – See text page 116; Fig. 5.11a. The colour of a mineral is one of its most obvious features. However, it is generally not a diagnostic feature. Some minerals can be identified by their colour, but many minerals can show a variety of colours in different specimens. 2. STREAK – See text page 117; Fig. 5.11b. While it is common practice in the laboratory to use a streak plate as described in the text, it is more usual in the field to scratch the mineral with the point of a knife blade or geological hammer (while also evaluating mineral hardness) and to rub the thumb over the powdered mineral to obtain its streak.
    [Show full text]
  • Volume 35 / No. 7 / 2017
    GemmologyThe Journal of Volume 35 / No. 7 / 2017 The Gemmological Association of Great Britain Contents GemmologyThe Journal of Volume 35 / No. 7 / 2017 COLUMNS p. 581 569 What’s New AMS2 melee diamond tester| p. 586 MiNi photography system| Spectra diamond colorimeter| Lab Information Circular| Gemmological Society of Japan abstracts|Bead-cultured blister pearls from Pinctada maculata|Rubies from Cambo- dia and Thailand|Goldsmiths’ S. Bruce-Lockhart photo Review|Topaz and synthetic moissanite imitating rough diamonds|Santa Fe Symposium proceedings|Colour-change ARTICLES glass imitating garnet rough| Thanh Nhan Bui photo M2M diamond-origin tracking service|More historical reading Feature Articles lists 598 The Linkage Between Garnets Found in India at the 572 Gem Notes Arikamedu Archaeological Site and Their Source at Cat’s-eye aquamarine from Meru, the Garibpet Deposit Kenya|Colour-zoned beryl from By Karl Schmetzer, H. Albert Gilg, Ulrich Schüssler, Jayshree Pakistan|Coloration of green dravite from Tanzania|Enstatite Panjikar, Thomas Calligaro and Patrick Périn from Emali, Kenya|Grossular from Tanga, Tanzania|Natrolite 628 Simultaneous X-Radiography, Phase-Contrast from Portugal|Large matrix opal and Darkfield Imaging to Separate Natural from carving|Sapphires from Tigray, Cultured Pearls northern Ethiopia|Whewellite from the Czech Republic| By Michael S. Krzemnicki, Carina S. Hanser and Vincent Revol Inclusions in sunstone feldspar from Norway and topaz from Sri 640 Camels, Courts and Financing the French Blue Lanka|Quartz with a tourmaline
    [Show full text]