Avalon Eidolon, earlier versions vs Diamond

I own Eidolons and listened to the Diamonds about 3 years ago at the dealership where I bought the Eidolons. This was not a back-to-back comparison. However it was immediately clear that where the Eidolons are laid back, the Diamonds were considerably more resolute throughout the spectrum, and a bit more dynamic. They had more, and deeper, bass due to the longer throw woofers, and the tops were quite a bit more open and extended. It wasn't possible in the room to judge issues like bass integration around the crossovers. The Diamonds sounded like the more refined and expensive of the two, however the dealer owned Eidolons himself, and said he personally preferred them to the Diamonds, which he found to be more agressive and less musical than Eidolons. YMMV of course.

Any speakeer that comes with a diamond or diamonds or diamond dust,is more expensive than one without. Now the next question is does the hardness of a diamond mean anything in terms of sonics given that they add mass.
I think the carborundums (saphires) are next on the Moh's scale of hardness of well known gemstones. Don''t use Opals they are as soft as buttah.