Gemology Hub | Gemstone & Mineral Identification Guides

  Gemological Instruments and their use S# Name of Instrument Use 1 Polariscope   Polariscope is useful instrument to determine whether the stone is singly refractive (SR) or Double refractive (DR) 2 Refractometer(portable) Refractometer is use for Refractive index (RI) of gemstone. 3 Dichroscope (portable) Dichroscope is use for Pleochroism in gemstones. If the gemstone is pleochroic then it should be Double refractive.   4 Spectroscope(portable) Spectroscope is use for to determine the spectrum of gemstones. With the help of spectroscope we can easily separate same colors gemstones for example ruby, red glass and garnet. 5 Ultraviolet Lamp (portable) Ultraviolet is use for to determine Fluorescence effect in gemstones. With the help of this instrument we can separate natur...

Weight and price UNIT OF WEIGHT Ø     Gemstones are sold by weight. Ø     Large ornamental and rough material may be sold in kilogram (Kg) or gram (gm). Ø     Gemstone  weight is given in Carats. Ø     Carat is denoted by “Ct”                                                  1 Ct = 0.2 gm                                 5 Ct = 1.0 gm Ø     Each carat is split into 100 cents or  points  1.00 Ct = 100 cents or points 0.50 Ct = 50 cents or points 0.01 Ct = 1 cents or points 

  Basic Terms used in Gemology Real or Natural gemstones: Real or Natural Gems are those which are entirely the product of nature and unaltered by humans in any way, except for ordinary cutting and polishing. Treated gem: Any gem material which has been altered by humans, beyond ordinary cutting or polishing. For example Diffusion sapphire, Glass filling Ruby, dying, heat treatment etc.   Synthetic gems: Same as natural gem ( in terms of composition, structure, properties and appearance), except made by man. Or The Gems which have natural counterpart. For example Synthetic Ruby, sapphire etc. How to grown synthetic quartz in laboratory by hydrothermal process?   Simulant or imitation : A material ( Natural or Synthetic), Which has the same appearance as the gem it imitates(look like) but different chemical composition. For example Cubic Zirconia imitating Diamond, Red Garnet is the imitation of Ruby.   Assembled gems or composite gems : A gem mater...

What is Gemstone? Gemstone is a natural, inorganic or organic substance that has substantial beauty, rarity, and durability. Organic Gems: An organic gem is one that was made by living things, present or past. Examples include pearls, coral, jet, ivory, shell and amber. Inorganic Gems: Inorganic gems are those which are created by geological process and (usually) dug from the ground. 1.Beauty 2. Rarity 3. Durability Beauty   To be considered a gem, a material must possess to a large degree this preliminary qualification. Beauty in gemstone may depend on such qualities as color, transparency, luster, brilliance, pattern, optical phenomena and, in some cases, distinctive inclusions. 2.          Rarity This is a valued attribute of gems. It is natural for man to esteem most highly the things, which are hard to obtain, and this can come about if the gemstone is simply unavailable in the marketplace, or genuinely scarce(limited or short supply) in nature, e...

What is mineral? Mineral is defined as the substances which have the following catachrestic Naturally occurring   Inorganic Defined chemical composition Orderly atomic structure.  

Gemology is the scientific study of gemstones. It is concerned with the study of gem materials, including identification, testing methods and the basic knowledge of crystallographic, chemical, physical and optical properties of the gemstones. What is a Gemologist? A gemologist is someone who can identify the gemstone with the help of Instruments. Gemologists give a business added credibility. Career prospects in Gemology: Following are the career prospects for a Gemologist: Entrepreneurship in Gemstone dealing (the semi precious varieties do not cost a great deal!) Working as a gemologist with any of the renowned jewelers. Working or setting up your own laboratory for gem testing or gem identification. Pursuing further research in gemology or diamond grading. Creating your own designs in traditional or modern jewelry. Working as jewelry designers in fashion institutes. If you are a geologist you can focus your doctorate or post ...

  Lapis Lazuli  3   The ornamental material lapis lazuli can be classed as a rock rather than as a single mineral species. It consists of lazurite, sodalite, nosean and haüyne, the four members of the sodalite mineral group. These species occur mainly in association with leucite or nepheline in nepheline syenites, phonolites and related undersaturated igneous rocks (Deer, Howie and Zussman [DHZ] Rock-Forming Minerals , second edition, vol. 4B (2004; ISBN 1862391440)). Framework silicates. Silica minerals, feldspathoids and the zeolites . Lazurite and sometimes sodalite are occasionally found in contact metamorphosed limestones. The name lapis lazuli is usually given to the typical lazurite-rich rock which usually includes brassy yellow pyrite crys- tals, calcite and a colourless pyroxene. Nassau (2000) describes how it was discovered that ...