1. 珍珠
    A pearl is a hard round object which is shiny and creamy white in colour. Pearls grow inside the shell of an oyster and are used for making expensive jewellery.

pearl

    e.g. She wore a string of pearls at her throat...
           她戴了一串珍珠项链。
    e.g. I put on the pearl earrings Daddy had bought me.
           我戴上了爸爸给我买的珍珠耳环。

2. 珍珠般的
    Pearl is used to describe something which looks like a pearl.

    e.g. ...tiny pearl buttons.
           珍珠般的小纽扣

3. 明珠暗投；对牛弹琴
    If you say that someone is casting pearls before swine, you mean that they are wasting their time by offering something that is helpful or valuable to someone who does not appreciate or understand it.

    e.g. You do not value what should be valued, I see I was casting pearls before swine.
           你不重视应该重视的东西，我觉得我是在对牛弹琴。

4. 精辟见解，睿智言论，妙语如珠（常指开玩笑的话）
    People describe what someone says as pearls of wisdom to suggest that it is wise or helpful, often when they are joking.

pearl

    e.g. And what is that pearl of wisdom supposed to mean?...
           那番精辟见解到底是什么意思呢？
    e.g. Her advice includes perfectly true but rather fulsome pearls of wisdom.
           她的建议中有完全正确的金玉良言，但有过于恭维之嫌。