Answered by Shaykh Ilyas Patel
I wanted to know if we are allowed to keep or believe in gemstones or crystals and their healing powers since I have a Muslim friend who believes in such things.
In the Name of Allah, Most Merciful and Compassionate
Allah Most High says:
Pursue not that which you have no knowledge of (Koran 17:36)
To believe that THINGS (i.e. gemstones, crystals, etc) have properties (other than what is supportable by the prophetic sunna) that cause benefit or harm independently of the will of Allah is unbelief (kufr), whether such properties are considered natural or supernatural. But the argument of such people that showing veneration (tazim) for the righteous or that obtaining blessings (tabarruk) through them or their effects constitutes worship of them or associating others with Allah (shirk) is not supportable by the prophetic sunna, which prove to the contrary, as may seen from the following hadiths:
Bukhari relates from Mahmud ibn Rabi, when the Prophet (Allah bless him and give him peace) performed ablution, the companions almost fought over the excess water.
Bukhari relates from Abu Musa that the Prophet (Allah bless him and give him peace) called for a vessel of water, washed his hands and face in it, spat a mouthful of water back into it and then said to Abu Musa and Bilal, drink from it and pour the rest over your faces and chests.
The Prophet (Allah bless him and give him peace) said:
Allah Most High says, One of My servants reaches daybreak, a believer, another an unbeliever. He who says, We have received rain by Allahs grace is a believer in Me and a disbeliever in the planets. But he who says, We have received rain by the effects of such and such a mansion of the moon, is an unbeliever in Me and a believer in the planets [if he thinks they have a causal influence independent of the will of Allah.
(Reliance of the Traveller pg 681)
Whoever goes to a psychic (Arraf) or fortune teller and believes what he says, has disbelieved in what has been revealed to Muhammad
From the above we come to know to believe in the healing power of gemstones, crystals falls in the category of unbelief (kufr) and the ALTERNATIVE is to seek and obtain blessings from the righteous, god-fearing people who live amongst our communities through their duas, making them blow after reciting a surah etc or making them blow in water and drinking it.
And Allah knows best