It is characterized by stain marks and dull color on the surface or by a rough gritty appearance.
焊錫表面有污染, 色澤暗淡且有粗糙的小顆粒呈現。

In ancientry，not only did the great people have transnormal brightness ，but also with gritty will.
古之立大事者，不惟有超世之才，亦必有坚忍不拔之志。

The White House, however, seems intent on not becoming embroiled in some of these nitty gritty disputes.
然而在白宫, 他并不热衷于卷入细节纷争之中。

In every case of successful person in the ancient time, he's not only has excellent ability but also has gritty wills.
古之立大事者，不惟有超世之才，亦必有坚韧不拔之志。