There are other equivalent words. For instance, 珍珠 for pearl (I actually never heard anyone use 珠 alone）. No idea what "vermilion" means in your question. If it

There are other equivalent words. For instance, 珍珠 for pearl (I actually never heard anyone use 珠 alone）. No idea what "vermilion" means in your question. If it refers to the color, then you can say “朱红” or “朱红色”. In fact, very few words in spoken Chinese are monosyllabic, so it is highly unlikely to confuse a chemical element with other things. Moreover, you can always say "chemical element" + 元素 (element) or 原子 (atom) if you are afraid of confusing people; for instance, 氢原子，碳元素, though it is hardly necessary, as I never encountered the problem the author described in my 5+ years of studying chemistry in Chinese.