Pyroxeres are currently the best ore in low sec because of EVE Echoes ISK it's nocxium output. They have the very best deal in ISK/m3 now as long as nocxium's value stays up around 2000 ISK they should stay one of the best ores in low sec. Hemorphite is the move to ore for Zydrine that has become a staple in all blue prints which are tier 7 or greater.
Spodumain is the 2nd best ore in low sec and is your best ore to mine if your looking for the base minerals: tritanium, pyerite, mexallon, and isogen that are used in every ship blueprint in the sport in large quantities. Spodumain's worth has endured from afk high sec retriever mining because most of it has outputs can be easily gathered in high sec. But it remains a solid choice if your company is based in low or null sec and you are wanting to gather these minerals yourself rather than buying them from the commerce hubs. Dark Ochre is your ideal ore to be mining for when your target is to assemble nocxium, as it's the highest noxcium ouput in the match per m3. Gneiss has tanked in cost because of mexallon losing near half it's value per unit over the last week along with pyerite and isogen falling off in value appreciably. Gneiss, just like spodumain is only feasible to mine in case you do not want to make trips into the trade hubs to buy the minerals.
When looking at the reprocessing values at the base line you can see that all these require significant investment in reprocessing abilities to acquire some value from reprocessing them into Cheap EVE Mobile ISK nutritional supplements. Hemorphite and Gneiss shouldn't be reprocessed at current prices because eve at perfect reprocessing skills you would not be breaking even in value.