Gemstones

I found this on choosing gemstones by colors:
http://jewelry.about.com/od/birthstonefactsandfolklore/a/gemstones.htm
It gives a few suggestions based on a few colors.  Another way to be able to choose gemstones is to go for each one.  Can be a long search when there are many to look at.  It left me wondering if there is a general guide to help people choose gemstones.  I just would like a guideline that can be applied to many gemstones all at once.  Are they are all different?

I look elsewhere, like youtube.com but I haven't found any good reliable guideline for choosing gemstones in general.  It is the same as above.  It goes with colored or specific stones and how to choose them.  I did found one that was a general guideline but it was a bit new agey and mainly on crystals.  I don't have anything against new age.  It is just not exactly what I am searching for.  I just want a general unbiased guideline to choose gemstone.  I don't have time to research for each stone and sometimes, I don't know which gemstone I will take.  I think I am not the only one here with this problem.

I guess I haven't found the perfect guide to choose gemstones.  Or I haven't choosen the right words to do my research.  So, I have to come back on this, redefine the words and what I am searching for.  It is a question of time and the right wording to find what I am searching for.  I do like gemstones and rocks.  I do like working with them.  It add something special to my jewelry projects.  It isn't just color.  The precious stones had a beauty in themselves, the beauty of a rock that happened to be colored.