Is money earned from manufacturing and selling silver ornaments and jewelry that contain 100% copper—based on customer request and at a reduced price of up to 75% of the agreed-upon price—halal or haram?

If it is highly probable that customers will sell jewelry made of copper as gold or silver, then it is not permissible to manufacture it, and the money earned from it is unlawful (haram). This is because it involves cooperation in deception, as Allah Almighty says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." And the Prophet, peace and blessings be upon him, said: "Whoever cheats is not from me." However, if their deception is not known or not highly probable, then there is no harm in manufacturing it.