This is the 18240th most frequent Russian word.
чистого
"Чистого" means "pure" or "clean" in English.
In this sentence, "чистого" is used to describe the purity of gold, indicating that the gold is unalloyed or unmixed.
Это было чистого золота.
It was pure gold.
Here, "чистого" refers to the juice being natural, without additives or mixtures.
Я хочу стакан чистого сока.
I want a glass of pure juice.
In this context, "чистого" is used metaphorically to describe the heart as morally pure or kindhearted.