I’ve been waiting all day to add my two cents worth. Please consider the following two links. (BTW PETERCP4E: I think our TRUE HARDS are cut from the same block).
https://sharprazorpalace.com/hones/1...hetstones.html
https://sharprazorpalace.com/hones/1...true-hard.html
A few points in no order of priority. 1. Among the TRUE HARD category of novaculite stones, color is not a determiner of density. Others words, not a spits worth of difference between translucent, hard black, or any other color variation of TRUE HARD.
2. While individual stones may slightly vary in density or individual persons may test their stone’s density, the best that can be said generally is the TRUE HARD category is 2.5+ on the GS scale. (See Dan’s Whetstone chart).
3. I know some go to extraordinary lengths to burnish and polish their stones. It’s a lot of work and IMHO unnecessary. Moderate to light burnishing will achieve excellent results. See attached related thread.
Please review my previous threads. Hope they’re helpful. I’ve got all three: translucent, hard black, and true hard. They perform exactly the same, which is to say magnificently.