CBG (Cannabigerol) is known as the 'stem cell cannabinoid' or the 'mother of all cannabinoids'. This is because CBG is the original molecule that all other cannabinoids come from.
Over time, the acidic form of CBG - CBGa, breaks down into CBDa, CBCa, and THCa. When subjected to heat, light, or naturally over time, these acidic forms begin to convert to CBD, CBC, and THC.
CBG Oil is expensive to make as the hemp plant produces very low levels of CBG, normally less than 1% of the plant's total weight. This means more raw materials and work are needed to produce significant levels of CBG when compared to extracting CBD.