What is the ruling on trading gold over the phone and the internet, where the amount or weight is delivered hours later or the next day, and is this considered usury (riba)?

If the father sells or buys gold over the phone or the internet and delays possession, this is impermissible because possession is a condition at the time of the contract for gold. To correct this, one can appoint an agent to take possession at the time of the contract. If what happens over the phone or internet is merely a non-binding promise, then this is permissible according to some scholars. Some scholars hold the view that manufactured gold is not subject to usurious rules, but the majority of scholars disagree with this.