Orkhon is also called Old Turkic or Göktürk script. It was used mostly in Mongolia and Western China, but there are dialects that were used in Siberia (Yenisei) and Kazakstan.
Orkhon is sometimes called Turkic Runes because of their angular shape, and there are enough similarities to Futhark that there are a number of people who argue passionately that Orkhon is the ancestor of Futhark. While I acknowledge that there is a familial relationship, I tend to agree with the faction which says that the relationship is that they are both distant descendants of Phoenician, and that Orkhon appears to be a descendant of a non-cursive Sogdian.
Futhark is definitely an alphabet, like the writing systems neighbouring Scandinavia. Orkhon is sort of like an abjad, like many of the writing systems in the vicinity of Mongolia. This to me is the most persuasive argument.
The earliest Orkhon artifacts that are known date from the early 700s, and the earliest Yenisei from the 800s, while the earliest Futhark artifacts date from 160 AD. This is not difinitive proof that Orkhon did not influence Futhark: earlier Orkhon artifacts might have been written on perishable objects (which perished). The strong dialectical differences between Yenisei and Orkhon (Mongolian) suggest to me that Yenisei and Orkhon diverged at an earlier point than the early 700s. However, this would also argue that Futhark and Orkhon would have needed to diverge at an even earlier point than 160 AD, which I have a harder time believing. If the Scandinavians traveled widely enough in 100 BC to meet the Mongloians and take the script, why didn’t they meet up with the Latins first and take the Latin script?
Orkhon is unusual in two ways:
- Orkhon is the only writing system I know of (yet) which is written right-to-left in rows, but writing the rows from bottom-to-top. (The only other script I know of that goes bottom-to-top at all is Tifinagh, which sometimes was written vertically in columns from bottom-to-top.)
- Turkic languages have vowel harmony, which means that words only have either front vowels or back vowels. While vowels were frequently not written (like abjads), the consonants were written differently depending upon whether the next vowel was a front vowel or back vowel. Thus it has more vocalic information than a strict abjad, but less information than a strict alphabet.