search
  • Inicie Sesión
    Registrarse
  • Servicio al cliente sólo en inglés

    Número gratuito - EE. UU. & Canadá únicamente:
    1-800-464-1640

    Internacional:
    +66-39303404

  • Cambiar idioma
  • USD

Certified Gemstones

In the gemstone trade, many gemstones offered for sale are certified to guarantee their authenticity. As a buyer, it is important to understand the different forms of certification, and the types of agencies that provide these certificates.

First, it is critical to understand the difference between an identification report and an appraisal. A gemstone identification report is issued by a trained gemologist, and summarizes the results of scientific testing of the gemstone. On the other hand, an appraisal is an attempt to estimate the financial value of the item and is issued by an appraiser who may or may not be certified. An appraisal is essentially an opinion based on market knowledge, whereas an identification report is the result of objective measurement.

Gemstone Identification Report

Although many buyers are concerned above all with the value of their gemstone, a dependable identification report is actually more worthwhile. An identification report will state whether your gemstone is natural or synthetic, and whether (in the case of a natural gem) it has been treated in some way. Clearly this information is essential in order to provide a financial appraisal of the gem.

In principle, any trained gemologist could issue an identification report on a gemstone. But in practice, gemstone dealers depend on independent gemological laboratories for certification of their gems. There are several reasons for this. First, it is unethical for dealers to issue certificates for gems that they are selling, due to potential conflicts of interest. Secondly, modern gem identification requires sophisticated diagnostic equipment that is expensive and complicated to use. The best gemological labs also see many thousands of gems each year, so they have experience that far exceeds that of any individual gemologist.

Detecting gem treatments is the most demanding task faced by gemological labs. Treatments include simple heat treatment, fracture-filling, irradiation and diffusion treatment with various chemicals. Gemologists use a variety of techniques to detect these treatments, including microscopic examination of gem inclusions, energy dispersive X-ray fluorescence (EDXF) spectrometry, laser induced breakdown spectrometry (LIBS) and Fourier transform infrared (FTIR) spectrometry.

  • Primera publicación: May-21-2010
  • Última actualización: January-22-2019
  • © 2005-2019 Reproducción (texto o gráficos), sin el consentimiento expreso por escrito de GemSelect.com (SETT Compañía Ltda.) es estrictamente prohibida.
Pinterest Board Names
More Shapes
Piedras Preciosas Populares
  • Zafiro
  • Esmeralda
  • Rubí
  • Aguamarina
  • Circón
  • Ópalo
  • Topacio
  • Turmalina
  • Granate
  • Amatista
  • Citrina
  • Tanzanita
Todas las gemas (142)
A B C D E F G H I J K L M N O P R S T V Z Á Ã Ó
  • Aguamarina
  • Aguamarina Ojo de Gato
  • Amatista
  • Amazonita
  • Ametrina
  • Amolita
  • Andalucita
  • Andesina Labradorita
  • Apatita
  • Apatita Ojo de Gato
  • Augita ojo de gato
  • Azurita Druzy
  • Berilo
  • Berilo Dorado
  • Calcedonia
  • Calcita
  • Charoita
  • Chrysocolla
  • Cianita
  • Circón
  • Citrina
  • Coral
  • Coral Fósil
  • Cornalina
  • Crisoberilo
  • Crisoprasa
  • Cromodiópsido
  • Cuarzo
  • Cuarzo Ahumado
  • Cuarzo Fresa
  • Cuarzo Limón Estrella
  • Cuarzo Místico
  • Cuarzo Ojo de Gato
  • Cuarzo Rosa
  • Cuarzo Rosa Estrella
  • Cuarzo Rutilado
  • Cuarzo con marcasita
  • Diamante
  • Diásporo con Cambio de Color
  • Diópsido Estrella
  • Doblete de Ópalo
  • Enstatita
  • Escapolita Ojo de Gato
  • Escolecita
  • Esfalerita
  • Esfena
  • Esmeralda
  • Esmitsonita
  • Espectrolita
  • Espinela
  • Fluorita
  • Fluorita con Cambio de Color
  • Fucsita con Rubí
  • Gemas de estrella
  • Gemas de jade
  • Geoda ágata
  • Granate
  • Granate Alamandino
  • Granate Demantoide
  • Granate Espesartina
  • Granate Estrella
  • Granate Grossularita
  • Granate Hesonita
  • Granate Malaya
  • Granate Piropo
  • Granate Rodolita
  • Granate Tsavorita
  • Granate con Cambio de Color
  • Grandidierita
  • Hematita
  • Hemimorfita Druzy
  • Hiddenita
  • Howlita
  • Idocrasa
  • Iolita
  • Jadeíta
  • Jaspe
  • Kornerupina
  • Kunzita
  • Labradorita
  • Lapislázuli
  • Larimar
  • Madreperla
  • Malaquita
  • Mali Granate
  • Matriz Ojo de Tigre
  • Maw-Sit-Sit
  • Morganita
  • Nuummite
  • Obsidiana
  • Obsidiana Copo de Nieve
  • Ojo de Gato Actinolita
  • Ojo de Halcón
  • Ojo de Tigre
  • Ojos de gato
  • Peridoto
  • Perla
  • Piedra de Luna
  • Piedra de Luna Arco Iris
  • Piedra de Luna Estrella
  • Piedra de Luna Ojo de Gato
  • Piedra de Sangre
  • Piedra del Sol
  • Piedra del Sol Estrella
  • Pietersita
  • Pirita
  • Pirita Arco Iris
  • Prehnite
  • Rodocrosita
  • Rodonita
  • Rubí
  • Rubí Estrella
  • Rubí-Zoisita
  • Serafinita
  • Serpentina
  • Silimanita
  • Silimanita Ojo de Gato
  • Sodalita
  • Sugilita
  • Tanzanita
  • Topacio
  • Topacio Imperial
  • Topacio Místico
  • Turmalina
  • Turmalina Cromo
  • Turquesa
  • Variscita
  • Venturina
  • Zafiro
  • Zafiro Estrella
  • Zafiro con Cambio de Color
  • Ágata
  • Ágata Dendrítica
  • Ágata de Fuego
  • Ópalo ojo de gato
  • Ópalo
  • Ópalo Boulder
  • Ópalo Chocolate
  • Ópalo Moss
  • Ópalo Negro
  • Ópalo de Fuego
  • Ópalo en matriz
Main Categories
  • Nuevas llegadas
  • Lotes de gemas
  • Las Piedras Preciosas Calibradas
  • Piedras preciosas por pieza
  • Gemas de grado superior
  • Pares Emparejados
  • Gemas Corte Cabujón
  • Drilled Gems, Briolettes and Beads
  • Piedras zodiacales
  • Las Tallas de Piedras Preciosas
  • Gemas elegantes
  • Gemas de estrella
  • Zafiro sin Calefacción
Servicio al cliente sólo en inglés

Número gratuito - EE. UU. & Canadá únicamente:
1-800-464-1640

Internacional:
+66-39303404

Ahorra Dinero
No hay gastos de envío para artículos adicionales
$8.90 envío en todo el mundo

Update Translation
 
Current Value
New Value
GemSelect Gemstones
X Cerrar ventana
Colored Gemstones
X Cerrar ventana
Colored Gemstones
X Cerrar ventana
Colored Gemstones
Tamaño y peso

Gems are always measured in Millimeter (mm)

Dimensions are given as;
length x width x depth,
except for round stones which are;
diameter x depth

Select gems by size, not by weight!
Gem varieties vary in density, so carat weight is not a good indication of size

Note: 1ct = 0.2g

Size Comparison Chart