How can I control the size of an ore vein

Status
Works as designed
Issue description

I made a mod that added a topaz ore to the game. I made the topaz toolsrelatively strong because i wanted topaz to be of medium rarity. Well, it is or medium rarity, but the veins of topaz ore are generate with like 10 blocks per vein. That's too much! I can't see an option to change this, though. Can you show me how? If there is no way, then this is a suggestion!

Issue comments

You have frequency per chunks and frequency on the chunk sliders to control ore spawning rates.