If one is relying exclusively upon a gemstone to pass a test there are all kinds of considerations. The subject matter of the test, the day of the test. It can get quite complicated.
Therefore let me share a story with you. When I was 10 my grandmother gave me a clear quartz crystal shaped like a what we use to call a "nickel marble". She taught me to set the crystal on an old coke bottle that was placed on the table where I did my homework. There was always a white candle burning on her kitchen table in the evenings where I did my homework. I would then take the crystal to school. Being in the Mountains of North Carolina (the buckel of the evangelical Bible belt) the crystal was always just assumed to be a marble for recess.
I took many a quiz and test with that crystal in my left hand and pencil in my right.
Still have that crystal, still use it when I am researching a subject or studying something.[img][/img]