This holds the kiln at 1760F. While the firing schedule at https://glazy.org/recipes/111576 also holds an hour at 1600F and 1500F this focus on a single temperature is likely better. To improve crystal development try holding at 10, 20, 30, 40 and 50 degrees hotter and colder to find the best temperature. Then try holding for longer and shorter periods at that temperature.
We have also found that the C6DHSC slow cool schedule (100F/hr from 2100 down to 1400) grows the iron crystals well. This is very convenient since that schedule is used often in our studio.
138°C/hr to 121C
250°F/hr to 250F
Evaporate all mechanical water
194°C/hr to 1148C
350°F/hr to 2100F
60°C/hr to 1204C
108°F/hr to 2200F
Slow down to even out kiln chamber
555°C/hr to 1148C
999°F/hr to 2100F
Heal blisters, pinholes here
555°C/hr to 960C
999°F/hr to 1760F
Grow iron crystals here
Start temperature assumed: 25°C or 75°F
"Fahrenheit degrees" is not the same as "degrees Fahrenheit".
A 100° reading on a Fahrenheit thermometer is equal to a 37° reading on a Celcius thermometer.
But "100 Fahrenheit degrees of temperature change" is equivalent "55 Celsius degrees of change".
That is an important distinction to understand the above temperature conversions.