PROFESSIONAL GRADE ACID GOLD TESTING KIT We offer ONLY professional grade superior quality gold testing acids accurately graded for 10K, 14K, 18K, 22K gold. Platinum and Silver Acid included. Our testing stone is GENUINE PURE BLACK gold testing stone not to be confused with cheap glass gray color imitation or slate, made in Germany Stone measures approximately 2" x 1-3/8" x 1/2" thick. Each acid bottle is color coded as well as imprinted with corresponding karat. All acid bottles are equipped with precision dispensing nozzle allowing precise amount of acid to be dispensed, preventing spilling, and unnecessary waste of the acid. All acids provided are fresh and of the original manufacturer strength. Used by Professional Jewelers to determine correct Carat of gold when buying scrap or checking new arrivals. INSTRUCTIONS FOR USE Just scratch the stone with tested jewelry and place a drop of acid on the scratch. If scratch remains on the stone without fading or turning green than it is the same as the karat of the testing acid. If it fades away you may want to test it with lower karat acid to determine if it's 10K instead of 14K, or 14K instead of 18K and so forth. If it does not hold 10K acid than it is simply not gold. When using the Silver or Platinum acids, scratch the stone with the silver or platinum piece. If the scratch remains then the test is successful. If it disappears then the test fails and the piece is not Silver or Platinum. It is used this way by thousands of jewelers all over the world. KEEP AWAY FROM CHILDREN! INTENDED FOR PROFESSIONAL USE ONLY! No liability is accepted due to improper use or accidental spilling. Replacement acid bottles are sold individually and can be purchased separately.