This little blighter stowed away and travelled to Australia in a bag of coffee from Colombia. If I had not seen this tiny piece of concrete, smaller than a coffee bean, it would have easily cracked the ceramic burrs in my Porlex grinder. 99.9% of the time coffee companies will catch foreign material in a de-stoner before it can make it into bags of roasted coffee destined for customers’ kitchens. It’s still worth keeping an eye out for stowaways in your coffee through. Your grinder will thank you.