Jewelleries are made for women and not men. As such, men cannot wear earrings, bangles, chains or any adornment. Only a silver ring is allowed for him. The beloved prophet SAW made gold haraam for men and halaal for women:

قَالَ خَرَجَ عَلَيْنَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَفِي إِحْدَى يَدَيْهِ ثَوْبٌ مِنْ حَرِيرٍ وَفِي الْأُخْرَى ذَهَبٌ فَقَالَ إِنَّ هَذَيْنِ مُحَرَّمٌ عَلَى ذُكُورِ أُمَّتِي حِلٌّ لِإِنَاثِهِمْ ابن ماجة

The beloved prophet SAW came to us with one hand he was holding a cloth of silk and on the other hand, he had gold. He addressed to us saying: ‘‘These two are haraam upon the male of my ummah and they are halaal on the females.’’(Ibn Majah)

Hence, it is not permissible for men to wear gold rings, watches and pen also. Rings of white gold or platinum also not permissible for men.
Silk cloth are also haraam for men.

Furthermore, according to sunnah, it is not permissible for men to wear rings made of any metal other than silver (Abu Dawood). And that also the ring should not exceed 4.37 grams (One Misqaal)-Ibn Hibbaan. Some ulamas are of opinion that men should not wear rings for adornment purposes nor as a jewellery (Shami). The sunnah of wearing a silver ring was for administrative and sealing purposes. But others advocate that it is permissible for men to wear a silver ring for any purpose due to the fact that the beloved prophet SAW gave the permission to a sahabah to wear a silver ring that does not exceed 4.37 grams-Nassai.

Both men and women should not wear rings made of iron, brass, copper and lead. Because these have been mentioned as being used to construct idols or used to punish hell dwellers as mentioned in the Qur-aan(Shami). But it is permissible for both to use an iron ring that is plated with silver-Baihaqi.

In fact women are restricted on rings on only silver, gold and white gold only. This restriction of gold and silver for women is only for rings only.

This restriction is not on other women jewelleries like bangles, chains, etc. As such women are NOT allowed to wear fake rings, but they are allowed to wear fake jewelleries(other than rings), metal or glass jewelleries. Her jewelleries can be made of anything that beautifies to the condition that it does not specify itself as being a symbol or famously worn by non muslims. The habit of wearing these jewelleries should not belong specifically to a certain sect of non muslims. If the jewellery has no belonging and is generally worn, then it is permissible for muslim women to wear these in front of their husband or inside the house, not exhibiting to the public.

Earrings and nose rings are permissible for ladies ONLY. But haraam to do piercing on other parts of the body.

‘’And tell the believing women to lower their gaze and be chaste and not expose their adornment except that which [necessarily] appears thereof and to wrap [a portion of] their headcovers over their chests and not expose their adornment except to their husbands, their fathers, their husbands’ fathers, their sons, their husbands’ sons, their brothers, their brothers’ sons, their sisters’ sons, their women, that which their right hands possess, or those male attendants having no physical desire, or children who are not yet aware of the private aspects of women. And let them not stamp their feet to make known what they conceal of their adornment. And turn to Allah in repentance, all of you, O believers, that you might succeed.’’(24:31)

A married woman is strongly recommended , from times to times, to beautify herself discreetly for her husband after Esha.

Gold for medical prescription:

Hazrat Arjafah r.a., a male sahabi, was given the permission to use a silver nose to cover his slit nose(Abu Dawood). When silver was deemed inappropriate, then the beloved prophet SAW told him to use a golden nose. This permission is on medical prescription. But we may note the matter of precaution and ihtiyaat to the extent that the beloved prophet SAW recommended only in silver in the beginning. Then because of necessity and convenience, he ordered for gold. And yet the issue was of necessity and zarourat. Hence men cannot wear watches made of silver, gold or platinum. Women may wear these because they may wear gold, silver, platinum, etc.

But permissible for men to put a golden teeth, in case medically prescribed. Haraam for both men and women to wear teeth jewellery, teeth gems, dental jewellery diamond, etc. Permissible to adjust the teeth, have fillings, fake teeth etc on medical prescription only.

Worth mentioning this hadith for our knowledge:

عَنْ عَبْدِ اللَّهِ قَالَ لَعَنَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الْوَاشِمَاتِ وَالْمُسْتَوْشِمَاتِ وَالْمُتَنَمِّصَاتِ وَالْمُتَفَلِّجَاتِ لِلْحُسْنِ الْمُغَيِّرَاتِ لِخَلْقِ اللَّهِ ابن ماجة

Hazrat Abdullah bin Mas`ood r.a. said: ‘’(Allah Ta`ala and)the beloved prophet SAW cursed the one who apply tattoo, the one who is being tattooed, the one who remove eye brows, the one who space between the teeth for beauty purposes; those who change the creation of Allah(change physical aspects of the body).’’ Ibn Majah;Muslim.

Piercings, women cutting hair, silicone breast implants, etc fall under the curse of Allah and the curse of Rasouloullah SAW.

Note: Although gold items or silk are haraam to be used or worn by men, but a male muslim may sell or buy such items.