Reference for Yoma 89:1

שדומה לפז זהב שחוט שנטוה כחוט זהב סגור בשעה שנפתח כל החנויות נסגרות זהב פרוים שדומה לדם הפרים

because it resembles [the shining jewel] paz. Spun gold, because it is spun like a thread. Locked [rare] gold, because when its sale is opened, all other shops are being locked up.<span class="x" onmousemove="('comment',' For as long as such gold was obtainable in one shop, none would go to buy in any other.');">¹</span>

Jastrow

Jastrow