Sheikh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
With regard to counting with date stones and pebbles and the like, that is alright and some of the Sahaabah (may Allah be pleased with them) used to do that. The Prophet (peace and blessings and of Allah be upon him) saw the Mother of the Believers counting tasbih with pebbles and he approved of her doing that; it was also narrated that Abu Huraira counted tasbih with pebbles.
With regard to (counting tasbih) with beads put together on a string, some of the scholars regarded it as makrooh and some of them did not. If the intention behind it is good, then it is good and is not makrooh.
But as for using it when there is no need to do so, or making it visible to people, such as hanging it around the neck or wearing it like a bracelet on the wrist, and the like, this is either showing off to people or gives rise to suspicion that one is showing off, and is resembling the show-offs unnecessarily. The former is haram and the least that can be said about the latter is that it is makrooh.
End quote from Majmoo‘ al-Fataawa (22/506)
