How to Identify Ruby Simulants and Synthetics

Key Takeaways for Identifying Ruby Simulants and Synthetics

In this article, you’ll learn the following:

• How to distinguish rubies from most ruby simulants with basic observations and tests
• How the optical and physical properties of the most common ruby simulants differ from those of ruby
• Why flame-fusion rubies are the only synthetic rubies most gemologists will likely ever examine
• How to distinguish flame-fusion rubies from natural rubies with just a microscope and a little practice

A Brief Review of Ruby’s Chemical and Crystallographic Properties

• Ruby belongs to the corundum mineral species. This species includes all varieties of sapphire, too.
• By definition, red corundum is ruby. Corundum with any other color, including colorless, is considered sapphire.
• All corundums form in the hexagonal (trigonal) crystal system and grow naturally as six-sided crystals. Rubies tend to form as flat, tablet-like crystals. Sapphires tend to form as double pyramid-shaped crystals.
• Pure corundum is a colorless aluminum oxide with the chemical formula Al₂O₃. When different metal impurities are captured during the growth process, the crystals will have different colors.
• Ruby’s red color comes from minor traces of

• Key Takeaways for Identifying Ruby Simulants and Synthetics
• A Brief Review of Ruby's Chemical and Crystallographic Properties
• Initial Gemological Observations
• Magnification
• Inspecting the Ruby's Surface
• Basic Gemological Tests for Rubies
• Specific Gravity
• Pleochroism
• Absorption Spectrum
• Fluorescence
• Refractive Index
• Identifying Rubies with Advanced Gemological Tests
• Raman Spectroscopy
• UV-vis-NIR Spectrometry
• Elemental Analysis
• Common Ruby Simulants or Lookalikes
• Glass vs Ruby
• The Glass Molding Process
• Testing Glass
• Plastic Resin vs Ruby
• Spinel vs Ruby
• Testing Spinels
• Garnet vs Ruby
• Testing Garnets
• Rubellite vs Ruby
• Testing Rubellites
• Cubic Zirconia vs Ruby
• Testing CZ
• Ruby Simulants Identified
• Properties of Ruby vs Ruby Simulants
• Synthetic Ruby vs Natural Ruby
• Flame Fusion Ruby vs Natural Ruby
• How Flame Fusion Works
• Where are Flame Fusion Rubies Made?
• Testing Flame Fusion Rubies
• Flux-Grown Ruby vs Natural Ruby
• How Flux Growth Works
• Testing Flux-Grown Rubies
• Hydrothermal Ruby vs Natural Ruby
• How Hydrothermal Growth Works
• Testing Hydrothermally Grown Rubies
• Pulled Ruby vs Natural Ruby
• How Pulling Works
• Testing Pulled Rubies
• Advice for Novice Gemologists
• Ruby Simulants and Synthetics References

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