Jobs particularly focused on the staircases, which echoed the one he had built at NeXT.
When he visited a store as it was being constructed, he invariably suggested changes to the staircase.
His name is listed as the lead inventor on two patent applications on the staircases,
one for the see-through look that features all-glass treads and glass supports melded together with titanium,
the other for the engineering system that uses a monolithic unit of glass containing multiple glass sheets laminated together for supporting loads.
In 1985, as he was being ousted from his first tour at Apple,
he had visited Italy and been impressed by the gray stone of Florence's sidewalks.
In 2002, when he came to the conclusion that the light wood floors in the stores were beginning to look somewhat pedestrian
a concern that it' s hard to imagine bedeviling someone like Microsoft CEO Steve Ballmer
Jobs wanted to use that stone instead.
Some of his colleagues pushed to replicate the color and texture using concrete, which would have been ten times cheaper,
but Jobs insisted that it had to be authentic.
The gray-blue Pietra Serena sandstone, which has a fine-grained texture,
comes from a family-owned quarry, Il Casone, in Firenzuola outside of Florence.
"We select only 3% of what comes out of the mountain,
because it has to have the right shading and veining and purity," said Johnson.
"Steve felt very strongly that we had to get the color right and it had to be a material with high integrity."
So designers in Florence picked out just the right quarried stone, oversaw cutting it into the proper tiles,
and made sure each tile was marked with a sticker to ensure that it was laid out next to its companion tiles.
"Knowing that it's the same stone that Florence uses for its sidewalks assures you that it can stand the test of time," said Johnson.