Edward Bristol recommends:
Further readings and links

Gemstone Treatments
Current Top-Notch Know-How of the Trade 

Natural Rubies Only
The first natural ruby site on the web (by Wild Fish)

Wild Fish Gems on Facebook

Wild Fish Gems on Twitter

The 14th Dalai Lama
The first philosopher to connect modern science with the Buddhist concept of Karma.

World Gem Guide
Database of gemstones from vendors all around the world.

ibodywise:
News and know-how around healing and well being.

GIA
The official gem side of the Gemological Institute of America.

Confused about ringsizes?

GemDB.com
Database project for the professional gem trader or ambitious shopper.

Gemstone Energy Medicine - Free Course
Visit the site of Isabelle Morton , founder of Gemstone Therapy Institute and the leading authority on gemstone energy medicine. Isabelle pioneered gemstone sphere therapy in the 1980's with her book, "Gifts of the Gemstone Guardians," authored under the name Ginny Katz. She is also an intuitive healer. Sign up for a free gemstone energy medicine course on her website.

Rosehartwellbeing
Health and healing from Australia.

Faceters.com and Cabbers.com
A complete source for faceting rough, learn how to facet, faceting supplies, gemstones, and gemstone related information.

Your gemologist
Information on gemology, training, gemstone forums, very informative.

Jewelry Blog
Professional blog on jewelry making.

The American gem trade association
All you want to know about the gem trade. 

Richard Hughes
Most entertaining and profound reading on sapphire and ruby.

Vincent Pardieu
Gem traveler with lots of interesting trip reports.

Ganoksin
For the jewelry manufacturing industry.

Colored Gemstone
Online magazine on colored gemstones.

Gemstone Therapy - Free Course
Sign up for free gemstone therapy course today, presented by Isabelle Morton, world leading authority on gemstone therapy and founder of the Gemstone Therapy Institute. Gemstone therapy, a.k.a. gem therapy, is the art and science of healing body, emotions, mind, and spirit using either therapeutic gemstones, or remedies imparted with gemstone energy.

Appraiser
Find a gem appraiser on palagem.

Astrologer
Find an astrologer.

GAAJ
Gemology for Japanese.

Mineral Database
Probably all there is to know about minerals.

AIGS
AIGS provides gemological training at the school and gemological testing at the AIGS gemstone testing and research laboratory.

GemologyOnline
Forum around gemology.

Color Theory
All you might want to know about colors.

JVC
Ethical board of the jewelry industry.

MindBodyHealing.com
Alternative Healing Color Light Therapy - Color Light Therapy Sessions for physical, emotional, mental and spiritual health and wellness, formulated according to traditional Ayurvedic healing knowledge of color.

Jewelry Link Exchange
A human edited directory of jewelry sites.

Jeweler Seek
Links to jewelry - antique, custom and handcrafted, wholesale, manufacturers, distributors of jewelry, online shopping, gemstones, diamonds, diamond rings, watches, necklaces and others.

Jewel Info 4 U
Jewellery, Aquamarine, Amethyst, Pearl and Other Gemstone Information