• Graphite is found naturally ( or occurs in nature ) in Siberia, Ceylon, ...
• Ferroso ferric oxide occurs naturally as magnetite.
• Graphite is found naturally ( or occurs in nature ) in Siberia, Ceylon, ...
• Ferroso ferric oxide occurs naturally as magnetite.
Циммерман М., Веденеева К.. Русско-Английский научно-технический словарь переводчика. Russian-English scientific dictionary for translators. 2012