Answered by Shaykh Yūsuf Badāt
Is it okay to drink chai (tea) that has deer horns crushed and mixed in it? It is ginseng chai (tea).
Jazāk Allāh for contacting us with your concern.
In general, it is an agreed upon principal amongst the Fuqahā (Islamic jurists) those parts of a dead animal or carcass which do not contain life, such as wool, hair, teeth, nails, bones and horns are pure (ṭāhir).
Ibn Abbās (may Allah be pleased with him) states,
“The Messenger of Allāh simply prohibited the flesh of the dead carcass. As for the hide, hair and wool, there is no objection in (making use of) it”. (Al Dār Quṭnī)
Ibn Abbās (may Allah be pleased with him) says,
“A sheep belonging to Sawdah bint Zam’ah died. She addressed the Messenger of Allāh (peace and blessings upon him) informing him about it’s death. The Prophet (peace and blessings upon him) said, “Why did you all not benefit from its’ hide?”. They questioned, “Can we utilize the hide of a dead sheep?”. The Prophet (peace and blessings upon him) told her, Allāh has stated “Say, “I do not find, in what has been revealed to me, anything (out of the cattle under discussion) prohibited for anyone who eats it, unless it be carrion or blood that pours forth, or flesh of swine (6:145). You are not eating the flesh of it, [so] if you tan (dry) it (the hide), you may benefit from it”. It is reported in the same narration that she used the hide to make a drinking vessel. (Musnad Aḥmad)
And Allāh Knows Best