The word has now been used to numerous writing systems, including Hieroglyphic Hittite, Mayan hieroglyphs, and early Cretan. Meroitic is the sole direct successor of Egyptian writing and has no link to Egyptian hieroglyphs. Hieroglyphs on the Kom Ombo Temple in Egypt. Modern conservation efforts have revealed that some hieroglyphs are actually pictures, not characters. A picture written with ink on papyrus would fade over time unless another material was used instead. The choice for this alternative material was clay, which could be shaped or modeled into new objects. These new objects could then be painted with vivid colors and decorated with gold or silver leaf to create sacred texts for use in worship. Hieroglyphs are the oldest known human language and were used by Egyptians for thousands of years before being replaced by Greek around 300 B.C. Although no actual documents have been found dating back this far, scientists can tell how old certain hieroglyphs are by how many times they've been reused in newer writings. For example, the symbol for "house" had probably already been used by artists in some form or another before it was finally assigned a phonetic value as &ldquogl;kha-nis”. It's possible that this same house was even included in earlier drawings or sculptures but since it was meaningless without explaining its meaning, it was ignored by everyone except for later historians who wanted to know about ancient Egyptian houses.