(N/A) Boron is a typical non-metal.
Aluminium is a metal but shows many chemical similarities to boron,while gallium,indium,thallium,and nihonium are almost exclusively metallic in character.
Boron is a fairly rare element; it mainly occurs as orthoboric acid $(H_{3}BO_{3})$,borax $(Na_{2}B_{4}O_{7} \cdot 10H_{2}O)$,and kernite $(Na_{2}B_{4}O_{7} \cdot 4H_{2}O)$.
In India,borax occurs in Puga Valley (Ladakh) and Sambhar Lake (Rajasthan). The abundance of boron in the earth's crust is less than $0.0001 \%$ by mass.
There are two isotopic forms of boron: $^{10}B$ $(19 \%)$ and $^{11}B$ $(81 \%)$.
Aluminium is the most abundant metal and the third most abundant element in the earth's crust ($8.3 \%$ by mass) after oxygen $(45.5 \%)$ and $Si$ $(27.7 \%)$.
Bauxite $(Al_{2}O_{3} \cdot 2H_{2}O)$ and cryolite $(Na_{3}AlF_{6})$ are the important minerals of aluminium. In India,it is found as mica in Madhya Pradesh,Karnataka,Orissa,and Jammu.
Gallium,indium,and thallium are less abundant elements in nature.