In the middle of the dharma chacra or dharma wheel, there is a swirling central hub, composed of 3 or 4 sections. Each section represents a ‘gem’ capable of yielding enlightenment. These gems differ, depending on the ‘tradition’ that is depicting them. (In Tibetan Buddhism these traditions can be either Nyingma, Kagyu, Gelug, Sakya or Bön-Dzogchen.)
In Taklung Kagyu, where my teacher is from, there are 4 spiraling Gems.
The first two gems are ‘lineage’ and ‘experience’, the other two are methods of practice typical for the Taklung Kagyu teachings.
All gems have to be practiced together if one wants to be enlightened. The main thing is that we have to understand the essence of dharma with single pointed mind and single pointed faith.
The swirling gems come together in a single point. This point represents ’emptiness’. The realization of emptiness has to be so touching that all reasoning, ideas and concepts of the mind are completely stripped down.
In the center there is nothing, however, all the gems come out of that center.
This emptiness is extremely overwhelming and cannot be grasped by words or thoughts.