3、Selection of Chroma：
     Chroma is the percentage taken up in the workfloor of Diamond.
     Select high chroma in the case of coarse granularity, coarse grinding requires the high efficiency, not a high requirement to the coarseness of the working surface, broad workface of grinding tools; contrarily select low chroma.
     Resinoid binder grinding tools ordinarily select chroma between 75-100%.
     Metalic binder grinding tools ordinarily select chroma between 75-100%.
     The relationship between Diamond chroma and content

Granularity	Content (carat／cm3)	Diamond volume in the Diamond floor
50	2.2	12.5%
75	3.3	18.75%
100	4.4	25%