I want it to use to propagate ficus plants from stem cuttings. It calls for soil and course sand.
The traction grit was made from clay. There is sand next to the traction grit. I am not sure if anyone uses this kind of sand in the soil.
I live in Philadelphia, PA
The reference you were reading about rooting Ficus cuttings is woefully out of date if they are suggesting using "soil". Throw that book out. Or quit reading Facebook and Reddit forums. Go for more authoritative sources, like BNut. LOL. Actually MOBOT, Missouri Botanic Garden website, is one of the other better "consumer friendly website.
Regardless of source, for better houseplants, plants in pots, bonsai, etc. The use of "soil" from the garden, or harvested from more exotic locations has largely been abandoned as being the source of many problems, including insects and plant pathogens. Stop using "dirt".
A very good media for rooting cuttings is a blend of peat and fine perlite. Nearly as good is a blend of peat and the all purpose sand. A "modern" substitute for peat is coir, a fine shredded product make from coconut husks. Coir lasts many years in use, where peat decomposes in a few years. Coir is near pH neutral, where peat is acidic. Depending on species, the acidic reaction of the peat can be desirable. Ficus are not fussy about pH, either peat or coir will work ideal.
Peat, coir, pelite, fine pumice, small amounts of vermiculite, and all purpose sand, are all good "soil-less" components for making a media suitable for rooting cuttings and or sprouting seed. Sift to remove dust, and remove particles larger than 1/8th inch. If you have too wide a variation of particle size air penetration will be compromised. The more uniform the particle size the better the water retention and the air penetration. For rooting cuttings 1/16th thru 1/8 is a good size bracket for cuttings.
I would use 1:1 peat and perlite, or 1:1 coir and perlite. If you have vermiculite, a blend of 2:2:1 of Peat or Coir, pelite, and vermiculite.
Diatomaceous earth - if available - can be used, it has high water holding capacity, and some cation exchange capacity (CEC) which helps holds fertilizer for use by the cuttings. Napa part number 8822 is a fine small particle form of DE, and can work well mixed with perlite, peat, or coir. I would not use DE at 100%, it is best as a component of a mix.
In general, components for rooting cuttings are small in particle size, and sterile. The minerals, such as pelite, pumice, vermiculite, DE, and sand are all inherently near sterile and can be heated in an oven to sterilize them if desired. (usually not necessary, but can be done if you like). An organic component is also used as part of the blend, peat and coir come in more or less sterile. They can be sterilized in an oven, or pasteurized by moistening and heating to 180 F or higher.
If you have pumice on hand, pumice and perlite can be substituted for each other if the particle sizes are comparable.
For raising from seed, particle size can be larger, 1/8 to 1/4 inch range. Seeding mixes can be made from any blend of the above components plus other components not mentioned, including akadama, pine bark, douglas fir bark, horticultural charcoal in moderate amounts, kanuma, diatomaceous earth and others that escape me at this moment.
Hope this helps
Leo