Great ceilings! are they a prefinished product?

yes, they are white oak prefinished, American Vintage Natural white oak

What is the material on the back of the island? Quartz or natural?

porcelian slabs by neolith basalt black https://www.neolith.com

I like the linear light fixture above both the island and table to tie them together visually. Is that something you had custom made specifically for that spot or is it a ready made system? By which company? And is it fluorescent or something else?

That was custom made design by architect. It is a combination of LED tape light (2700K, by DIODE LED) , KLUS housing and etched diffuser, off the shelf metal rods, and the wood by Matt Eastvold.

what is the name of the marble is on the island? it is gorgeous.

calacatta viola.

what material are the kitchen and island countertops?

neolith is the brand of the material, black basalt is the color/model

Can I ask what material you used for the island itself? Is this bookmatched?

the sides/back of the island are 1 1/4" slab (3 cm) calacatta viola. The slabs are bookmatched at the center and the slab is mitred and the pattern is continued around each side

My builder and I are working on achieving the color of the concrete that you created. What brand and color is the matte masonry sealer? Did you add anything else aside from the hard trowel finish and the sealer? It looks absolutely beautiful. Your project is the reason I decided to do concrete floors. Thank you in advance for your help.