Direct purchase of sand from khadan

Dear sir my client purchase sand, stonechips direct from khadan , he does not get any gst bill from khadan, but when he sells this sand and stonechips to big construction project he charges gst and generate gst bill by adding 5% gst and regularly deposited the gst amount to the goverment as out put tax. as he dos not get any gst input tax from khadan he deposited only the output tax. my question is that is this proceduure is write or wrong ? if wrong please give the right suggestion and how i show this amount of direct purchse of material from khadan in gst portal, please help me in this case. Thanking you YOUR TRUELY BISWANATH SANTRA EMAIL: [deleted]