Gemstones: Natural, Enhanced, or Manmade??

I see a LOT of sellers on ebay and etsy (and elsewhere) who are selling various stones as "gems" or "gemstones" when actually, they are man-made or simulated stones, or glass. A lot of fault lies with wholesalers and manufacturers, who try to make their man-made glass stones SOUND exciting and new (such as "Cherry Quartz" and "Pineapple Quartz") and sellers just pass that along to customers.

I'm compiling a list of all common stones, and will update it as I go. I'm listing them as "Natural," "Enhanced," "Dyed," or "Synthetic" (meaning man-made, such as glass). Please note that MANY gemstones are routinely enhanced which IS NOT a bad thing--most gems are treated in assorted ways to bring out their color and beauty, and most treatments are permanent. Also, there are lab-created stones that have the same physical, optical and chemical properties as their natural counterparts (such as lab-created emeralds, rubies, and sapphires - "precious" gemstones). There are even lab-created diamonds, which are NOT to be confused with CZ's or any other simulated stone! (I see "lab created diamonds" on ebay ALL the time when this is false - the stones on ebay are cubic zirconias or crystals!)

Per the American Gem Trade Association's (AGTA) Gemstone Information Manual, here is a partial list of some of the most common stones:

• African Agate: Natural
• African Jade: Natural
• African Opal: Natural
• African Turquoise: Natural
  
• Amazonite: Natural
  
• Amber: Enhanced
  
• Amethyst: Enhanced
  
• Apatite: Natural
• Aquamarine: Natural
• Arizona Turquoise: Stabilized
  
• Aventurine: Natural
• Azurite Malachite: Assembled
• Beryl: Natural
• Black Coral: Natural
  
• Black Onyx: Dyed
• Blue Agate: Synthetic
• Blue Goldstone: Synthetic
  
• Blue Lace Agate: Natural
• Blue Chalcedony: Natural
• Blue Quartz: Synthetic
• Blue Topaz: Enhanced
• Bronzite: Natural
  
• Calcite: Natural
• Carnelian: Dyed
• Cat's Eye: Synthetic
• Charoite: Stablized
  
• Cherry Quartz: Synthetic
• Chinese Turquoise: Stabilized
• Chrysocolla: Stabilized
• Chrysoprase: Natural
  
• Citrine: Enhanced
• Coral: Natural
• Corundum: Natural
• Cotton Candy Jade: Synthetic
  
• Emerald: Enhanced
  
• Emerald Jade: Dyed
  
• Garnet: Enhanced
• Goldstone: Synthetic (copper infused glass)
• Fluorite: Natural
• Green Garnet: Natural
• Green Jade: Natural, but often dyed
• Green Onyx: Dyed
  
• Green Hemimorphite: Natural
• Iolite: Enhanced
• Jasper: (all kinds): Natural
  
• Kunzite: Stabilized (!)
• Kyanite: Stabilized
• Lapis Lazuli: Natural
• Lava: Natural
  
• Laramar: Natural
  
• Labradorite: Natural
• Lavender Quartz: Dyed
• Lemon Quartz: Enhanced
• Lemon Chrysoprase: Stabilized
  
• Moss Agate: Natural
  
• Mother of Pearl: Natural
• New Jade: Natural
• Obsidian: Natural
  
• Ocean Jasper: Natural
• Olive Jade: Natural
  
• Olive Quartz: Natural
• Opalite: Synthetic
• Orange Calcite: Natural
• Peach Jade: Dyed
• Pearls: (Freshwater, Akoya) Natural, can be dyed
  
• Peridot: Natural
  
• Pineapple Quartz: Synthetic
  
• Pink Jade: Dyed
• Purple Jade: Dyed
• Rainbow Moonstone: Natural
• Red Aventurine: Natural
• Red Jade: Dyed
• Red Tiger Eye: Enhanced
• Rhodochrosite: Natural
  
• Rhodonite: Natural
• Rock Crystal: Natural
• Rose Quartz: Enhanced
• Ruby: Enhanced
  
• Rutilated Quartz: Natural
• Sapphire: Enhanced
  
• Sodalite: Natural
  
• Smoky Quartz: Enhanced
• Sugilite: Natural
  
• Tiger Eye: Natural
• Tourmeline: Enhanced
  
• Turquoise Quartz: Synthetic
• Turquoise: Stabilized, rarely (less than 8%) Natural, can be dyed
  
• White Jade: Natural
• White Opal: Natural
• Yellow Jade: Natural
• Yellow Opal: Natural
• Yellow Opalite: Synthetic

Stones can be Bleached, Coated, Dyed (for color intensity or uniformity), Filled/Impregnated (with colorless glass, plastic, solidified borax or similar substances, which are visible under 10X magnification, to improve durability, appearance and/or add weight), Heated, Heat and Pressure treated, Lasered (in diamonds, to alter inclusions), Oiled/Resin Infused/Waxed, Irradiated, and Stabilized (infused with clear resin to enhance hardness and deepen color).

If you have any questions, or additions to the list - please let me know!