Exotic Gems, Volume 3   

How to Identify, Evaluate, Select and Care For Matrix Opal, Fire Agate , Blue Chalcedony, Rubellite, Indicolite, Paraiba and Other Tourmalines



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Explore Tourmaline, Fire Agate, Matrix Opal & Blue Chalcedony  

Exotic Gems, Volume 3 is the third in a series of books that explains with close-up photos the price factors and identifying traits of unusual gems. The stones are shown not only loose but also in jewelry, in the rough and as beads. Fun facts, historical anecdotes, geographic sources, gem treatment information, cutting advice, and tips on gem care are included along with diagrams and tables to aid in identification and evaluation. If you’re interested in matrix opal, fire agate, blue chalcedony, Paraiba tourmaline, rubellite or other tourmalines, Exotic Gems can provide you with jewelry design ideas and in-depth information that will help you be a smart buyer and seller. Written in a succinct and user-friendly style, Exotic Gems: Volume 3 is an ideal reference for jewelers, sales associates, appraisers, gem collectors, gemology students, designers gem dealers and consumers.


by Renée Newman 

ISBN 978-0929975-48-1   

Paperback / 6" x 9"  / 136 pages / 422 color photos /

International Jewelry Publications / $19.95 


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The simple genius in Renee Newman’s Exotic Gems series is that no books like them have been written. Of course there are several places to find buying guides; a simple search for “gemstone buying guide” will yield many results. What these other guides cover however can be found within the first twenty pages of Exotic Gems. What follows in Volume Three, as with its predecessors, is a wholly comprehensive look at specific varieties of gems not commonly featured in jewelry store cases.

      Covered in Volume Three are four selections, including Matrix Opal, Fire Agate, Blue Chalcedony, and several varieties of tourmaline. For each of these gems is an entire section of Exotic gems designed to provide the reader with everything they need to know, whether caring for a gem they already have or seeking to purchase one. The stones are described in great detail, including origin, localities, varieties, care information, and possible treatments.

      The most represented stone in Exotic Gems Volume 3 is Tourmaline, and represented it surely is. Over sixty pages, Renee Newman describes the history of Tourmaline, it's chemical and optical properties, and each of the many unique varieties of tourmaline in depth. As you read through the book, there are also several very informative sections that many people aren't familiar with, including a section on the steps to cutting fire agate, and one on treated Andamooka matrix opal.

      Maybe the most impressive feature of Exotic Gems is its amazing wealth of photographs. Over 100 individuals and companies in the gemstone trade have donated their images to this volume alone, and the end result is a book that provides as much information visually as it does through Renee's excellent writing.

Jeweler's Ethics Association


This is the latest volume in Renée Newman’s library of delightfully illustrated and useful books. This edition focuses on some of the less commonly seen stones, including matrix opal, fire agate and the various members of the tourmaline family, which, although not the rarest gemstones, are deserving of more recognition than they currently get.

      Renée begins by looking at the factors that affect the value of these stones, and goes on to systematically investigate the properties of each stone, showing why they deserve the label of ‘exotic gems’.

      One interesting inclusion in the volume is that of pink tourmaline. Although probably not considered exotic by many, pink tourmaline quite rightly deserves a place because of its historical importance, being highly sought after by the Chinese Empress Dowager Tzu-hsi, who was laid to rest with a pillow carved from this much-beloved material. Stories such as this, interspersed throughout the book, bring the human element of gemstones and gemmology into what other texts might treat as a simple discussion of properties and effects.

      Nonetheless, the various optical effects of each stone are still covered and, in this respect, tourmaline is probably the most amazing stone. Standard uni-colour tourmalines are mentioned, followed by a discussion on the many varied colour effects that tourmaline is capable of showing. Renée notes that striping across the crystal is common, with many colours seen in various combinations, but also discussed is the concentric banded form (watermelon), along with the rarer chatoyant, colour-change and Usambara effect forms.

      Fire agate also features, with details on which of its iridescent colours are the most desirable and/or valuable, and the known sources worldwide. As with the section on tourmalines, detailed images of professional cutters are included, along with commentary from master cutters specializing in each material.

Matrix opal and blue chalcedony are the remaining two stones covered, and each is considered with the same level of care and attention to detail. When discussing blue chalcedony, Renée focuses on the different localities that this material can be sourced from — an important feature for collectors.

      The range and variety of colours and structures that this material takes are also covered, with various cutting styles designed to enhance these features.

      Matrix opal, which is often overlooked in textbooks in favour of the more ‘desired’ forms of precious opal, gets a well-deserved review, and the images included here show that this has a unique appeal all of its own. Different formations and localities are dealt with and even a form of synthetic matrix opal is included.

      Overall, this is another excellent addition to the famous and much-loved Renée Newman series. The information contained is wide-ranging, ensuring that there is something for everyone, whether amateur collector or serious gemmologist.     

Andrew S. Fellows FGA DGA, Gems & Jewellery, published by the British Gemmological Assn.(Gem A)  


. . . The book [Exotic Gems, Volume 3] is intended to be an ideal reference for consumers, jewelers, sales associates, gem dealers and collectors, gemology students, as well as appraisers. Newman continues to amaze the reader with a wealth of information regarding the lesser known colored gemstones. The author delves deep into the history, origin, geographic sources and any available or common gemstone treatments. Tables are included to aid the reader with the unique gemstone’s characteristics, such as refractive index reading, specific gravity, spectrum, reaction to UV fluorescence and magnification, stability to light, etc.

       Volume 3 explodes with numerous detailed, colored photographs of the exotic gems, both loose and mounted. The photos help the reader in understanding identification traits and certain value factors. Also of interest, are step-by-step photos with captions of How a Master Cutter Cuts a Tourmaline as well as Fire Agate.

       Exotic Gems is extremely well organized and quite easy and interesting to read. I look forward to adding all of the other volumes to my library collection; especially for the fun facts, historical anecdotes and exquisite photographs.   

       As a jewelry appraiser and gemologist, I feel that this information in particular will serve as a great reference; especially when we have very inquisitive clients asking, for example, why we don’t automatically label a blue-green tourmaline a “Paraiba.” The quality of the photographs and their individual reference information listed can also be a great asset to an appraiser; helping locate possible comparison gemstones, designers, and/or gemstone dealers.

       Renée Newman’s Exotic Gems series is full of important information that would be a great tool for any and all consumers who have an interest in purchasing these different, unusual and fascinating colored gemstones. At the low retail price of $19.95, how can we possibly pass them up?

Reviewed by Katy Bodenburg, GG, NAJA Appraiser


The rather lengthy subtitle of this superbly written book is “How to Identify, Evaluate, Select and Care for Matrix Opal, Fire Agate, Blue Chalcedony, Rubellite, Indicolite, Paraiba and Other Tourmalines. Geared toward the lapidary and jewelry artist rather than the specimen collector, the book offers a detailed chapter on the many factors involved in pricing gems, including color, clarity, transparency and brilliance.

      Throughout the 136 pages, the major emphasis is on the popular varieties of tourmaline, which fill seven chapters. The varieties are grouped according to color and source. The section on cutting tourmalines is particularly useful. 

       The skillful use of nearly 400 color images to highlight various gems and their characteristics makes this a delightful book to peruse. For jewelry designers, many photographs—several by my friend Frank Heiser— illustrate a great variety of creative designs.

      The earlier volumes in the Exotic Gems series deal with tanzanite, ammolite rhodochrosite, zulatanite, sunstone moonstone and other feldspars (Vol 1) and alexandrite andalusite, chrsoberyl cat’seye, kyanite, common opal, fire opal, dinosaur gemstone, tsavorite, rhodolite and other garnets (Vol 2).

      These books are must haves for the libraries of jewelry designers, gemstone cutters, and anyone who simply appreciates colorful gemstones.

Bob Jones, Rock & Gem

Renee Newman has created a niche for herself writing guides on different gem materials. Each one has been fact-filled and extremely useful as a buying guide for the general public and gem industry professionals alike. Exotic Gems, Volume 3: How to Identify, Evaluate, Select and Care for Matrix Opal, Fire Agate, Blue Chalcedony, Rubellite Indicolite, Paraíba and Other Tourmalinesis the latest book in her Exotic Gems series.
       "Exotic gems" are defined by the author and Merriam-Webster’s Dictionary as "gems that are of foreign origin and/or strikingly, excitingly or mysteriously different or unusual." The gems Newman discusses in this volume are certainly all of the above, and designers are using increasingly unusual materials to fabricate unique pieces of jewelry that reflect the individuality of their clients. 
       The book begins with a helpful chapter that describes pricing factors and explains why a particular gem is priced the way it is. With the use of excellent photographs, the value factors for different cuts and saturations are pictured in great depth to help explain the variances in price. Comparisons like this are mentioned throughout the book relative to each gem discussed, each with pictures to reinforce the concept. 
       Each gem type is described and discussed in its own chapter. In the case of tourmaline, there is a general chapter on the group, where the major species are listed along with their (complex) chemical formulas. Subsequent chapters are devoted to the various colors of tourmaline, where the proper terminology (e.g., verdelite for green, indicolite for blue) is clarified. A photographic journal of sorts, with captions and tips by master cutter John Bradshaw of Coast-to-Coast Gems, is included so that the importance of the rough’s orientation and the cutting process are properly understood. Terminology of the different colors of tourmaline (i.e. verdelite for green, indicolite for blue) is discussed and clarified. Following chapters on Paraíba and other copper tourmalines are meticulous descriptions of the history and sources of blue to green tourmalines; pink and red tourmalines; yellow, orange, and brown tourmalines; and multicolored tourmalines (including bi- and parti-color and phenomenal varieties). Tips on evaluation and care are given for each color group. It is truly amazing how much valuable information has been condensed into such an easy format.
       The chapter on blue chalcedony contains identification information, accompanied by many photos that exhibit beautiful designs using this unsung gem. Geographic localities follow and include Malawi; Namibia; Indonesia; Mexico; Washington, Montana, California, and Oregon in the United States; and British Columbia in Canada. Assessing the quality of blue chalcedony is discussed, covering hue, tone, saturation, transparency, uniformity of color, clarity, cut quality, and sometimes size and locality. Stability and treatments are listed, followed by a section on care of the material.
       Lovers of the elusive fire agate will be pleased to find an informative chapter on this gem. History, deposits, and price factors precede an excellent section on the cutting of this material. Photos and captions by master cutter Ryszard Krukowski of Fire Agate Art Studio explain exactly why so much expertise on the part of the lapidary is required to bring out the magic in the material. Tips on care of the finished product follow.ine  
Matrix opal is the last gem addressed in this guide. Newman explores Queensland boulder, Yowah and Koroit, Andamooka, Mexican, and Honduran opal. The type and amount of material within matrix can dictate enormous differences in price. Generally, Queensland boulder opal commands higher prices than other types of matrix opal so locality can make a difference. The amount or absence of play-of-color, and the type of background the opal is viewed against, can also influence value significantly. Generally, the dark and black body tones are the most prized, because those colors provide a greater contrast to the play-of-color.
       One of the most noteworthy aspects of Newman’s many gem-related books is her use of photographs to illustrate quality and showcase modern designs that effectively and beautifully utilize the materials. Details on locality, treatment of material, and care tips are always well researched.
       Exotic Gems, Vol. 3 belongs in the library of gem and jewelry appraisers as a quick and easy reference to the relative value factors of the stones discussed, and is also relevant for those who are lovers of unusual gem materials. 

Reviewed by Jo Ellen Cole, Gems & Gemology


Table of Contents

 1. Exotic Gems  9

 2. Price Factors in a Nutshell  12

        Price Factors Explained 12

            Color 12

            Clarity 14

            Transparency 17

            Shape 18

            Cutting Style 18

            Cut Quality 18

            Brilliance 19

            Carat Weight or Stone Size 20

            Treatment Status 20

            Copper, Chromium and/or Vanadium Content 20

            Geographic Origin 20

            Distinctness of Optical Effects (Phenomena) 21

         Colored Gem Pricing 22

  3. Tourmaline Group  23

          A Brief History of Tourmaline 23

          What is Tourmaline? 2

          Identifying Tourmaline 28

          Tourmaline Chemistry 29

          Tourmaline Species Characteristics in Brief 31

          Tourmaline Varieties 33

          How a Master Cutter Cuts a Tourmaline 34

          Cutting Tourmaline (by John Bradshaw) 38

          Caring for Tourmaline 38

  4. Paraiba & Other Copper Tourmalines  39

          What is a Paraiba Tourmaline? 42

          Identification of Cuprian Tourmaline 45

          Price Factors for Copper-Bearing Tourmaline 47                                                

          Alternative Terms for “Paraiba” 48

  5.  Blue to Green Tourmalines  49

          What is Indicolite? 49

          What is Chrome Tourmaline? 50

          Verdelite or Green Tourmaline? 52

          Blue-green Tourmaline 55

          Gray Tourmaline 56

          Identifying Green Tourmaline 57


  6. Pink & Red Tourmaline  58

          What is Rubellite? 60

          Evaluating Pink & Red Tourmaline 63

                        Sources of Pink & Red Tourmaline 64

  7. Yellow, Orange & Brown Tourmalines  66                    

  8. Multicolored Tourmalines 70

        Formation of Multicolored Tourmaline 72

         Liddicoatite 73

         Effect of Color Zoning on Pricing 74

         Pleochroic Multicolor Effect 74

         Multicolored Tourmaline Jewelry 75   


  9. Cat’s-eye & Color-change Tourmaline 79

       Color-change Tourmaline 81


10. Blue Chalcedony 86

        What is Chalcedony? 88

        Identifying Blue Chalcedony 90

        Geographic Sources of Blue Chalcedony 91

        Judging Blue Chalcedony Quality 97

        Caring for Blue Chalcedony 98


11. Fire Agate  99

       Fire Agate Price Factors 101

        Cutting Fire Agate 104

        Caring for Fire Agate 108


12. Matrix Opal 109

       Boulder Matrix Opal 112

        Andamooka Matrix Opal 120

        Honduras Matrix Opal 122

        Mexican Matrix Opal 124

        Identifying Traits of Opal 125

        Pricing and Evaluation of Matrix Opal 127

        Caring for Matrix Opal 130                   

        Bibliography  131  

        Index  134

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