Please help me identify this seashell from Asia

[greengreen]

Hi Dave,

Thank you for your information. My friend confirms that the spoons are made from the freshwater shell that I showed and they are made in SE Asia. I agree, the term "mother of pearl" can mean many types of shells, including this freshwater mussel as well as Trochus niloticus.

This can prove that this customer is so ignorant and unreasonable and as a result my friend's business got a bad product review which really does damage to his business. Others reading her review may think he's selling plastic spoons and don't buy. Actually the spoons are made with high quality, thick and very long and straight 4.5" and obviously too straight for being made from Trochus niloticus

My friend wants to write back to this customers to dispute her. Obviously, this customer knows little about shells but wanted to brag that she knows a lot (I am not sure how she could finish her degree)and made a damaging review. My friend was very angry because of this false statement review. Could you please help outline a letter or  what my friend should write in a scientific manner to dispute the customer's judgment?

Thank you,