Quarks:

1) Said to have 1/3 or 2/3 of the only value of electric charge ever demonstrably measured

2) Said to possess "properties" like "strangeness," that have no attributes, so not only can you NOT MEASURE the property, there is nothing TO BE measured

3) Said to possess "properties" that disappear incrementally in weak decays (without being carried away by other particles), so that by the time you get to stable matter the "property" is gone