Kieserite and Epsom Salts (Natural Magnesium Sulfates)

Kieserite (monohydrate magnesium sulfate) and Epsom salts (heptahydrate magnesium sulfate) are naturally occurring mineral forms of magnesium sulfate with distinct hydration levels and end-use profiles — kieserite is primarily a slow-release agricultural fertilizer, while Epsom salts serve pharmaceutical, personal care, and horticultural applications. The US schedule distinguishes the two at the 10-digit level: kieserite under 2530201000 and Epsom salts under 2530202000, enabling separate tracking of these commercially different grades. India and Germany lead US supply, with China also a significant source, reflecting both natural deposit availability and synthetic production capacity.