Answer:
There is no harm in using precious stones such as ruby, and gemstones, as adornment in a ring.
Sayyiduna Anas ibn Malik (may Allah be pleased with him) narrates:
كَانَ خَاتَمُ رَسُولِ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ مِنْ وَرِقٍ ، وَكَانَ فَصُّهُ حَبَشِيًّا .
“The ring of the Prophet ﷺ was of silver, and an Abyssinian (Habashi) stone was set in it.”
Hafiz al-Nawawi (may Allah have mercy on him) (631 – 676 AH) writes:
قَالَ الْعُلَمَاءُ: يَعْنِي حَجَرًا حَبَشِيًّا أَي فَصَّا مِّنْ جَزْعٍ أَوْ عَقِيقٍ فَإِنَّ مَعْدِنَهُمَا بِالْحَبَشَةِ وَالْيَمَنِ .
“The scholars take this to mean a Habashi stone, i.e., its gem was of jaz’ or aqeeq, for both of these are found in Abyssinia (Habasha) and Yemen.”
Moreover, the Shariah does not prohibit the use of stones. The original ruling is permissibility. However, some people hold strange and bizarre beliefs about stones; all of these are baseless. The benefits attributed to wearing these stones and the narrations about them are all “da’if” and “batil.” Any view based on them will also be da’if and batil.
There are false beliefs regarding the influence of stones, such as when, in our society, someone is seen wearing a precious stone, people ask: “Where did you obtain it?” and in reply its benefits are enumerated.
