Her Nazarites; rather, her eminent ones (just as Joseph is called n'zir ekhav,"eminent among his brethren"). The rendering of the Authorized Version is lexically possible, but is intrinsically improbable.
The Nazarites constituted too small a portion of the Jewish people to receive so prominent a place in the elegy. Rubies; rather, corals. Their polishing was of sapphire; literally, their shape was (like) a sapphire.
But the point in which the sapphire is compared to the bodies of the princes is evidently not the outline of its form, but its gleaming brilliant appearance; so that the Authorized Version is substantially correct.