An oblong crystal the size of a cigarette packet was next to a pair of dividers - suggesting it was part of the navigational equipment.

BBC: 'Viking sunstone' found in shipwreck

The work in Nature Communications can hide centimetre-sized objects, limited only by the calcite crystal's size.

BBC: Invisibility cloaking benefits from crystal-clear idea

For starters, Apple may use a new liquid crystal display technology and change the physical size of the phone.

FORBES: Apple's New iPhone Could Be Tall, Thin And Beautiful

Until recently the only equipment for spotting a suitcase bomb was an unwieldy machine the size of a refrigerator, using liquid nitrogen to cool crystal detectors down to 300 degrees below zero and taking hours to produce a reading.

FORBES: Stopping Porta-Nukes

Until recently the only equipment for spotting a suitcase bomb was an unwieldy machine the size of a refrigerator that used liquid nitrogen to cool crystal detectors down to 184 degrees Celsius below zero and took hours to produce a reading.

FORBES: Stopping porta-nukes