If the question has to do with buying and dealing in gold coins that have images of animate beings, then the matter is subject to further discussion.
1 – If these coins are used for adornment, whether they are worn or hung on walls etc., it is not permissible to sell them or deal in them. It says in Fataawa al-Lajnah al-Daa’imah, 13/74:
Whatever has an image of any animate being on it, whether it is a gold or silver coin or paper money, or it is fabric or an implement, if it is bought to be hung up on walls or other things which are not considered to be treating it in a disrespectful manner, then dealing in it is haraam, because of the general meaning of the prohibition on image-making and using images of animate beings.
2 – If these coins are currency that is in circulation, there is nothing wrong with carrying them and dealing in them. They are like the gold dinars that the Muslims used during the first century, before they had their own dinars during the reign of ‘Abd al-Malik ibn Marwaan (may Allaah have mercy on him). But that is only permissible when there is a need.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said:
As for a man carrying money with pictures of kings and presidents that the Muslims are faced with nowadays, this is an old issue which the scholars have discussed. The people used to carry European guineas on which there was a picture of a horse and knight, and they used to carry the French réals on which there was a picture of the head and neck of a bird. What we think about this is that there is no sin on a person who carries it because he has a need to do so, because a person has to carry some money in his pocket, and not allowing the people to do so would cause them hardship. Allaah says (interpretation of the meaning):
“Allaah intends for you ease, and He does not want to make things difficult for you”
“and has not laid upon you in religion any hardship”
It was narrated in a saheeh hadeeth that the Prophet (peace and blessings of Allaah be upon him) said: “Religion is very easy and whoever overburdens himself in his religion will not be able to continue in that way. So you should not be extremists, but try to be near to perfection and receive the good tidings that you will be rewarded.” (Narrated by al-Bukhaari). And he said to Mu’aadh ibn Jabal and Abu Moosa when he sent them to the Yemen: “Be easy going and not harsh, give glad tidings and do not put people off.” And he said to the people when they rebuked the Bedouin who urinated in the mosque: “Leave him, for you have been sent to be easy going, you have not been sent to be harsh.” (These two reports were also narrated by al-Bukhaari).
So if a man carries money or an identity card or a driving licence on which there are images, and he needs it or fears that he may need it, there is nothing wrong with that and there is no sin on him in sha Allah, for Allaah knows that he dislikes these images and does not approve of them, and that if he did not need it he would not carry it.
From Majmoo’ al-Fataawa, 2/280
The Standing Committee was asked the following question:
There are some issues which cause me a great deal of anxiety, one of which is the issue of the pictures on the money that we have and which we bring into the mosques in our pockets. Is our bringing it into the mosques one of the things that will make the angels leave, so that it is haraam to bring it in? Is this considered to be one of the things that are used in a disrespectful manner? Because images that are treated in a disrespectful manner do not prevent the angels from entering houses.
The Committee replied:
The pictures on money are not something that is under your control. You have no choice but to own money, keep it in your house and carry it with you so as to make use of it in buying, selling, giving gifts and charity, paying off debts and other purposes that are prescribed in sharee’ah, so there is no sin on you, even though this money is not usually handled with disrespect because of its value. Rather there is no sin on you, because that is due to necessity.
From Fataawa al-Lajnah al-Daa’imah, 1/485.
But if what is meant is buying gold coins with paper currency, there is nothing wrong with that if it is hand to hand, because the Prophet (peace and blessings of Allaah be upon him) said: “Gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates and salt for salt. Like for like, equal for equal, hand to hand. If you are trading different kinds of good, then sell however you like, so long as it is hand to hand.”
(Narrated by Muslim, 1587 from the hadeeth of ‘Ubaadah ibn al-Saamit, may Allaah be pleased with him).
The currency that exists nowadays is sui generis, and it comes under the same rulings as gold and silver. If you buy gold or silver with it, the transaction must take place immediately, because the Prophet (peace and blessings of Allaah be upon him) said: “If you are trading different kinds of good, then sell however you like, so long as it is hand to hand.”
And Allaah knows best.