He went from nothing to lots, ten carats to rock
10 carats refers to a smaller volume of gold. Most times, purity of gold is measured by its volume.
Rocks on the other hand signifies the jewelries are pure.
So he stepped up on his golds. This could also signify his cash. Meaning he got a lot richer.
The man Pac is telling this story about is similar to Pac in that he went from this:
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