These are center drilled long stick pearls at approximately 15.5inch long.
Pictures are taken from real strands with a penny to give you a sense of size, as the sizes are various. The length of the biwa pearl is approximately 3/5″ to 4/5″ long and the width is about 1/4″ to 2/5″ long. Because they are made of nature, they do come a little different as you can see from the enlarged strands.
Although the darker background picture made a huge difference between 2 colors due to different lighting. However, both pink and mauve colored have similar light pinkish overtone, except pink has a little more peach while the mauve color has a little purple overtone comparing with the pink color.