Is Fayalite magnetic?
Yes, fayalite is magnetic, ithas a magnetic susceptibilty of approx 33 SI units, similar to prryhotite.
Fayalite can scratch orthoclase but not topaz?
Fayalite has a hardness of 6.5-7 on the Mohs scale. Therefore itscratches orthoclase (hardness 6), but not topaz (hardness 8).
Can fayalite scratch orthoclase but not topaz?
Yes..in a high definition the Fayalite can be able to scratch the Orthoclase but not the topaz. If you look on the Mohs scale, the Orthoclase is not harder than the Topaz. So,
in clear words, yes!!