I've taken silicea for years. I've never heard it called silica so I did a search on it and found this link. You might want to check it out.
cell salts are something our bodies need. Pharmaceutical companies and the fda are the biggest reason there are such scares about simple products that our body needs. It's not cost effective for them to promote products that help us to 'heal ourselves'. So they will dispute anything or claim there is only minor help from the product. I've found that if I want to know about anything I just have to search for all the information I can find, (good and bad) and make my own decisions based on the knowledge I have gathered.
I use the copernic agent software program (it's free). It's a search browser that will bring up tons of links for any question you enter into the search.
Good luck.
Romney