https://books.google.lk/books?id=IOEDAAAAMBAJ&pg=PA112&lpg=PA112&dq=why%20diamond%20gem%20inclsions%20do%20not%20give%20a%20star%20effect&source=bl&ots=gFh7LEsevE&sig=ACfU3U05xWEI1Uirl8v4yIjVhKVKMKk-wA&hl=en&sa=X&ved=2ahUKEwiPqKSHqJ3pAhXixjgGHQtcDXAQ6AEwAHoECAkQAQ&fbclid=IwAR15pOW__MAhN1teItg3BXQdUu65iM4CJMuzDhd88FLFZIK9Rp-7hGBqq9E#v=onepage&q=why%20diamond%20gem%20inclsions%20do%20not%20give%20a%20star%20effect&f=false