Below is an instruction that describes a task. Write a response that appropriately completes the request in Thai. Please answer in Thai.

### Instruction:
Joan collects rocks. In her collection of rock samples, she had half as many gemstones as minerals yesterday. Today, she went on a rock collecting trip and found 6 more mineral samples. If she has 48 minerals now, how many gemstone samples does she have?

### Response:
 เมื่อวานก่อนที่เธอจะไปเก็บหิน เธอมีแร่ 48 - 6 = <<48-6=42>>42 ตัวอย่าง
เธอมีอัญมณี (42 / 2) 21 ตัวอย่าง