So you want to be able to give players the option of getting 40+ extra resources even at level 1 tradeskill? The effect that would have on the market would be pretty severe.
I think the current resource gain at the moment is good enough (maybe even too high), being able to get ~100 every 6 seconds at level 1k (if you have max ts boost, skill points, and at least some levels of the guild ts building). TS gems that give extra resources will soon enough flood the resource market to around 10-20gold per resource.
Example: Say people put 8 hours into tradeskills a day, thats 4430 ts attempts in a single day, at the max output of 46 gems thats an extra ~200k resources for a single person. Now there are at least 50 people over 51 so far, so no matter what level they are in a tradeskill that outputs an extra 10million resources (if all 50 people ts for 8hours in a day). Now can you truly expect that not to have a huge effect?
I've been saying for a long time that resources are overpriced. I personally sell them for a lot cheaper than the going rate. However, I see your point and agree that a change that big could impact the game negatively. So how about instead of +1 resource, it gives +1% boost? Right now, with just mith skills and the "Mason" from the warrior tree. You gain 115% bonus. With a % gem, you can raise this where your level in TS matters even more for the resources you would gain. At lower TS levels, you would gain very little, at higher levels you would benefit more. If you keep these gems at level 51 requirement. Then people will have to choose between leveling faster or getting more resources per auto.
Also, there are just over 50 people in the game that are level 51 or higher. Out of those, there are 5-6 that TS regularly. Off the top of my head(listing in case I'm wrong) those are Benfynyn, Zogrom, Earthpeople, Ahaa, Migitman25 and me. I don't think either option will really break the game or the economy as most of those TSers don't put many resources on the market but instead use them for their own professions or donate them to their clan.