The quote from book is from THE WEAR AND CARE OF RECORDS AND STYLI, by Harold D. Weiler, 1954.
The diamond dust is of no consequence - it is very fine sub-micron that really has no impact to record playback. As I say in the book (Chapter VI). This has to exist as a very, very fine powder and the finest diamond powder you can buy is 100,000 grit which is 0.25 micron. So, the diamond wear powder on the record is probably less which in the end becomes inconsequential so long as there is no cleaner residue.
If whatever wear byproduct powder that is produced by the diamond and the record is kept dry and free of oily and sticky residue, the stylus should move through this without any effect – not unlike a light coating of very dry powder-snow, it just blows around.
Now the jagged silica particles are something else, and its origins are likely natural aerosols that the book addresses in Chapter IV and can be very fine Sahara Desert sand - you can read further about aerosols at NASA.
Fundamentally, the electrical resistance of PVC is report as about 10^16 Electrical Resistivity of Polymers and Plastics - Table while diamond is reported as 10^16 to 10^18 Resistivity of Carbon, Diamond - The Physics Factbook. This similarity would tend to minimize any triboelectric effect and support the reports that the diamond does not cause static on the record. Otherwise, if you carefully read Chapter VI, Table IV, you will see where the triboelectric series is better quantified. Standard HDPE record sleeves are close to PVC which is why they are used, but they are far enough apart that if you quickly pull the record from the sleeve, there is some risk of developing a static charge on the record.