Rubies, Sapphires, etc. sounds a bit more sophisticated than going by color. 

My gut reaction was to do by gem because when looking at a sapphire I don't care the color sometimes as long as it is a sapphire

Then I realized all the gorgeous reds and green stones in particular we have had... I like to search by color sometimes and don't care as long as it is that color.

Truthfully the end result is that as long as the other gemstones are easier to find than they are now, anything is better.

I asked my husband who couldn't care less about gems in general and his answer was "search by type not color"

I like "color" over the term "semi-precious," which is a term that I understand many in the colored stone industry consider to be a little outdated these days.  Honestly, if there is a way to search for both – color and gem variety – that would be awesome. As clgwli wrote, someone may be totally species or variety oriented, regardless of color... like, "what does DBL have in the way of sapphires?" Or, "Does DBL have any tsavorite?" I suppose, however, the variety oriented types, could use the SEARCH feature to find their stones, that's what I would do, anyway.

I'm thinking that many people don't know gems enough (beyond sapphire, ruby and emerald) to know exactly what it is they may be looking for... but they DO know they want a "green" gem, for example.

The advantage to categories organized by "color" is that someone looking for emerald may stumble on tsavorite garnet or chrome tourmaline, two stones that may stand-in beautifully for emerald. In many cases, these stones would be better choices for jewelry than emerald anyway. However, one or both, may not have been considered without being "stumbled-upon" in the "Green Gemstones" category. Spinel, another example, is a gem that could please a sapphire- or ruby-lover, but might not have been thought of on its own.

Also, I imagine that color categories are more flexible over time as gem material comes and goes. For example, some years one gem will be "hot" in the market or relatively easy to access: think, fine Mahenge pink and red spinel. Another year, the same gem may be almost impossible to find. Color categories also work well for the "oddball" or "once in a lifetime" gemstone varieties that show up now and then, but are not normally in stock.

Also, as stock comes and goes, chances of finding an entire DBL color gemstone category empty of gem or jewelry stock are less than if you attempt a listing for each and every variety (which, D, you have said you can't to anyway).

sorry...blather.... blather... blather...  

Great input guys thank you!!!!

Maybe we should do a color drop down to start.
We've been going over more details than you can imagine so far.
I'm very easy going on this- like I really care what the site looks like

Seriously- I have to compromise in some areas now- we can add a gemstone name dropdown later- or add subcategories in the gemstone category....