如何用英文表達"心血結晶"這個詞?

心血 = 費盡心思的 = painstaking (needing a lot of care, effort and attention to detail)

結晶 = (crystal) 比喻 努力之後所得到的成果 fruitful result; achievement

"心血結晶"

the fruitful result of painstaking work

the acheivement of painstaking effort

Godfrey譯得貼切，但係佢寫係意見度，只可作為參考。

Godfrey is right in using an idiom "blood, swear and tears" to stand for心血.
http://idioms.thefreedictionary.com/blood,+sweat+and+tears
blood, sweat and tears - a lot of effort and suffering eg This house is the result of 3 years' blood, sweat and tears.

"心血結晶" = the fruit of blood, sweat and tears

fruit of something = the good result that you have from something,
blood, swear and tears = extremely hard work

心血結晶 = A masterpiece

This masterpiece is finished with blood & tears.

心血結晶==This is the result of spare no pains;
This is the result of spending lots of effort;
Working hard and get good result for one's pains;