On one of my many trips to India, I actually got to play tourist. Here is a detail of a section of inlay of the Taj Mahal. Those are actual ruby, emerald, and lapis, carved and placed by hand.
If you don’t know already, Taj Mahal is actually an elaborate tombstone, not a palace as many in the west have glorified it to be. Not that it’s not a gorgeous structure which took ambition and painstaking skill and effort.
Always amazed me that such beautiful architecture could be rooted in such sadness. The man whose love drove him to madness and left him to look at the Taj Mahal from a room across a river until he joined his love again in his final resting place.
Agra is also just so isolated within India as well. Even my breath was taken away the first time I saw the grounds, knowing full well what to expect. I can only imagine the stunned reaction of a western explorer journeying through India to find this.