I noted some time ago that the Serbian letter ћ is different from the Maltese letter ħ. The Serbian ћ is Cyrillic, and its upper case equivalent is Ћ, whereas the Maltese letter ħ is based on the Latin h, and its upper case equivalent is Ħ. Also they are pronounced completely differently, the Serbian Ћ/ћ is phonetically /ʨ/, a bit like English “tch”, and the Maltese Ħ/ħ much more like a heavy English “h” (the Maltese H/h without the cross stroke is much softer).
Indeed, the IPA symbol for the Maltese sound is simply /ħ/, using the Maltese letter; it’s found in several other Semitic languages – Arabic ḥa (isolated ح, initial حـ, medial ـحـ, final ـح) and traditional Hebrew ח (though apparently that tends to be pronounced more like /x/ by modern Israelis). I’m glad to see that some of the more obscure Caucasian languages have it too: ҳ in Abkhaz, xI in Avar, xъ in Chechen, хь in Kabardian. And a couple of African languages as well, according to Wikipedia: ḥ in Kabyle, one of the Berber languages of Algeria; and simply x in Somali. And finally a couple of Romance languages/dialects: g/gh in Galician, and j in Cuban Spanish.
This is all completely different of course from ℏ, which is Planck’s constant divided by 2π.
I hope that is clear.