Regarding the appearance of the wheels and their construction: they gleamed like chrysolite (beryl, olivine); and the four were made alike. Their appearance and construction were a wheel [set at a right angle] within a wheel.

Then I looked and behold, [there were] four wheels beside the cherubim, one wheel beside one cherub and another wheel beside each other cherub; and the appearance of the wheels was like a sparkling Tarshish stone (beryl).

“You were in Eden, the garden of God;
Every precious stone was your covering:
The ruby, the topaz, and the diamond;
The beryl, the onyx, and the jasper;
The lapis lazuli, the turquoise, and the emerald;
And the gold, the workmanship of your settings and your sockets,
Was in you.
They were prepared
On the day that you were created.