紫胶

例句：

1. 1. The ancient Chinese used to use this resin for sealing their books.
   古代中国人曾经用这种树脂来封他们的书。
2. 2. This type of resin is often used in the production of high-quality musical instruments.
   这种树脂经常被用来生产高质量的乐器。
3. 3. The purple color of the resin is due to its high content of a pigment called anthocyanin.
   这种树脂的紫色是由于它含有大量的称为花青素的色素。