Shaikh Bin Baz rahimahullah said:
I have a gold chain which the name of Allah is written on it. Is it allowed for me to use it or is that impermissible?
This gold chain which has the name of Allah or a verse of the Quran, it is necessary to leave it because he will enter the washroom with it. Leaving it off is better. He may place it in a humiliated place, so it is more deserving to change this chain by removing the Name of Allah so it will not be humiliated. This is because the Names of Allah are great and the chain may be placed on some property or thrown in a room or a box. So he will not care about it and something inappropriate may touch it. So leaving it is more deserving and cautious, venerating the Names of Allah, the Exalted. Take a new chain that does not have the Name of Allah, the Exalted. This is more deserving and cautious in order to protect the Names of the Allah from humiliation. Likewise, the clothing which has the Name of Allah or verses, it is not allowed to wear it because it is a means to humiliating it or impurity may fall on it from menstrual blood or other than it. Or it may be thrown and stepped on by the people or sat on by the people. So this is impermissible to wear. It is impermissible to make it into pillows because it will lead to humiliation by sitting on it or walking on it and the likes”
[Reference removed since it no longer exists]
This is in relation to women. As for men, it is impermissible for them to wear necklaces altogether as the Scholars have mentioned. This is because it is from imitating women.
Faisal Ibn Abdul Qaadir Ibn Hassan
Also the Permemnat Committee took the same view as found here