線文字a

Linear A is a variety of the Cretan script which was developed in Ancient Greece. Along with Cretan hieroglyphic, it still remains undeciphered.

Long story short: this script was discovered by archaeologist Sir Arthur Evans. Actually Linear A was the primary script used in palace and religious writings of the Minoan civilization. The vast majority of the inscriptions were written on tablets made of unbaked clay, some of which have survived due to the fact that they were touched by some fires or arsons. Some inscriptions are inked on vessels and other objects. The shape of the signs suggests that the main material for writing was not clay, but parchment or similar material.

Linear A was the origin of the Linear B script, which was later used by the Mycenaean civilization. In the 1950s, Linear B was largely deciphered and found to contain the early form of Greek. Although the two systems share many symbols, this did not lead to a subsequent decipherment of Linear A. Using the values associated with Linear B, Linear A mainly produces unintelligible words. If it uses the same or similar syllabic values as Linear B, then its underlying language appears unrelated to any known language. This has been dubbed the Minoan language.