Rune Languages

Or Elemental Languages. In each of Elemental Realms of Glorantha in otherworld, Gods World, dominant magical languages are known. People of Mundane World use them for religious purpose, displaying their strong magical nature:

Darkspeech
Used by Uz and Underworld entities. See also Darktongue

Seaspeech
Mainly used by deepest Triolini Races, like Gnydrons, Niiads and Tritons

Earthspeech
Probably used by the earth cult members like that of Ernalda

Firespeech
Used commonly by the sky cults and sky entities like Certamus, and such like the cult of Yelmalio, Dara Happans and Teshnans

Stormspeech
Used by Orlanthi religious and Nar Sylla. See also Storm Tongue

Diamondspeech
Maybe not official, used by the cult of Caladra and Aurelion

Greg Stafford's Statement About Elemental Speeches(2001)
NO written form of Stormspeech exists. HOWEVER, the Lhankor Mhy script of the “highest level” is used to write down things in the language of the gods.

Their multiple scripts include one that is "common," and that is the one called Storm Script. It is Common because it is the one that LM priests will allow other people to learn, and it is thus the most common one among the Orlanthi. This common script is also used (at times) to record the sacred words to speak in a ritual and thus might be used for Stormspeech. However, it does only an approximate job of transliterating the actual Stormspeech. The real speec must be spoken. Thus if you don't know the Stormspeech words you might not be able to recognize them written down. It would be like reading kanji words that were written in English.

Lhankor Mhy most often NEVER allow others in their culture to learn to read and write.

Each of the "tribes" of gods has a natural sound of its own. The water tribe is the sounds of water, the ocean and also the silence of the depths. These sounds all have meaning, and the meaning is the language of the gods. Water gods have Sea Speech. But they are languages of the gods, not scripts.

Does Dara Happa and Teshnos gods thus speak the same language? Ultimately, yes. However, the ultimate vocabulary is accessible only in the ultimate rites of the god, and to get to those Ultimate Rites we have to use the local language. So we speak to the Fire Gods in the Dara Happa version of the [Rune Languages#Firespeech|Firespeech]] first, and eventually when we hear ONLY the ultimate sounds of Fire we will be hearing/using the same language as the gods in Teshnos.

Note
Elementalism influenced relatively strong to early settings of Glorantha