 Why does Evans have difficulty identifying crystals?
The meteor, a pebble, a little larger than a match head, traveled through space and time since it came into being. The light from the star that died when the meteor was created fell on Earth before the first lungfish ventured from the sea. Portions of the turbine also volitized; idling at eight thousand RPM, it became unstable. The shaft tried to tie itself into a knot, and the blades, damaged and undamaged were spit through the casing. It was two days to sunrise, where Evans stood. It was just before sunset on a spring evening in September in Sydney. The shadow line between day and night could be seen from the Moon to be drifting across Australia. Evans, who had no watch, thought of the time as a quarter after Australia. Evans was a prospector, and like all prospectors, a sort of jackknife geologist, selenologist, rather. Once he followed a stampede to Yellow Crater, where he thought for a while that he had a fortune in chromium. The chromite petered out in a month and a half, and he was lucky to break even. Evans was about three hundred miles east of Williamson Town, the site of the first landing on the Moon. Evans was due back at Williamson Town at about sunset, that is, in about sixteen days. But his oxygen was too carefully measured; there was a four-day reserve. Four days reserve—plus one is five—plus sixteen days normal supply equals twenty-one days to live. By the light of this, he reinspected the steam system, and found about three gallons of water frozen in the condenser. This one had a tank and coils of tubing in the center of a curved reflector that was positioned to radiate the heat of the steam into the cold darkness of space. When the meteor pierced the turbine, the water in the condenser began to boil. This boiling lowered the temperature, and the condenser demonstrated its efficiency by quickly freezing the water in the tank. Evans sealed the turbine from the rest of the steam system by closing the shut-off valves. Then, if the pump wasn't blocked by ice, it would return the water to the boiler. The stars next to the sun shone as brightly as though there were no sun. They might have appeared to waver slightly, if they were behind outflung corona flares. When Director McIlroy came into his office, he found it lighted by the rising sun. This was to allow the air-conditioning system to function properly, and to prevent air loss in case of the highly improbable meteor damage.
 They were not actually crystals to begin with
 All of the crystals he found were very rare  He does not have much experience in doing so  They were not actually crystals to begin with  None of the crystals were native to the moon