More than one other fmod reviewed your thread; we agree with the initial moderation of your above-mentioned Item Discussion thread.
The forum specific rules allow for discussion of items and their prices which is different from your purpose. As you stated here, it's a craft skilling tip that you are offering; thus, if your thread had beeen more thoroughly developed about which gems generate a profit when cut, it could have been moved to the RS Guides subforum.
If you do plan to make a new thread in the RS Guides subforum, please make sure you provide support for your claims about which are benefical/why. I mention this because, for example, the wiki lists 9 gems' profitability or lack thereof and the ruby, which you want to highlight, is shown as having the least amount of profitability. In other words, it seems like there is more nuance or context to providing a gem cutting crafting tip than what you provided.