Augustus' Emerald Seal Ring

When I read I Claudius by Robert Graves I came across this reference to Augustus' emerald seal-ring:

"He handed Livia his seal-ring so that she might write letters to the Senate by his authority, recommending the banishment. (This seal, by the way, was the great emerald cut with the helmeted head of Alexander the Great from whose tomb it had been stolen, along with a sword and breast-plate and other personal trappings of the hero. Livia insisted on his using it, in spite of his scruples - he realized how presumptuous it was -- until one night he had a dream in which Alexander, frowning angrily, hacked off with his sword the finger on which he wore it. Then he had a seal of his own, a ruby from India, cut by the famous goldsmith Doscurides, which all his successors have used as the token of their sovereignty.)"

I am attempting to find Graves sources for this incident. Of course since this is a novel Graves may have made up parts of it.

Here is one:
Suetonius:

Life of Augustus 50: The first seal Augustus used for official documents, petitions and letters was a sphinx; next came a head of Alexander the Great; lastly his own head, cut by Dioscurides, the seal which his successors continued to employ. He not only dated every letter, but entered the exact hour of the day or night when it was composed.

18. About this time he had the sarcophagus containing Alexander the Great’s mummy removed from the mausoleum at Alexandria...

Lucretius On the Nature of Things

Lucretius explains the difficulty of explaining Greek concepts in Latin verse:

And well do I know Greek science is obscure and difficult to explain in Latin verse, above all when I must work with coined words where Latin is lacking and the concept new. But your great goodness and the hoped-for-joy of your sweet friendship bid me bear all toil, and keep me awake at work through cloudless night seeking not only words but verses too, to be bright shining lights before your mind, that you may see deep into hidden truth.

Francis Schaeffer has some interesting thoughts about language and memory. From: The God who is There:

Carl Gustav Jung (1875-1961) speaks of the collective unconscious which emerges from the race as a whole. I think he is mistaken in his thinking, especially in the evolutionary origin which he gives it. And yet there is a certain memory in a culture that is carried on in its language. Such a language-related memory, I suggest, is a better explanation for what Jung calls the collective unconscious (1).

Footnote (1)

My thinking has led me to believe that there is a collective cultural consciousness or memory which is related to words. I would suggest there are two parts to it: a collective memory of a specific race, and a collective memory of all men as to what man is and what reality is.

Thus man, in his language, “remembers” (regardless of his personal belief) that God does exist. For example, when the Russian leaders curse, they curse by God, and not by something less; and atheistic artists often use “god” symbols. This, I believe, is a deeper yet simpler explanation than Jung’s view of god as the supreme archetype arising (according to him) out of the evolution of the race. Moreover, in man’s language, man also remembers that humanity is unique (created in the image of God), and therefore words like purpose, love, morals carry with them in connotation their real meaning. This is the case regardless of the individual’s personal worldview and despite what the dictionary of scientific textbook definition has become.