Brown pearl is a kind of gem formed by resin fossils, which is mainly composed of resin and plant fragments. Its color is usually brown or yellowish brown, sometimes with red or orange spots. Brown beads were formed in paleontology about 40 million years ago, and were formed by long-term pressure and chemical changes of resin flowing out of trees. Brown pearls are usually used for jewelry making and decoration. Blood pearl is a special kind of brown pearl. Its color is crimson or dark red, and sometimes it has a blood-like transparency. The color of the snow slope is because it contains red blood or other organic substances, which may come from the remains of ancient insects or other creatures. Blood pearl is usually regarded as a rare and precious gem, which is widely used in jewelry and art production.