Limestone Quarry

(back blip 3 of 4)

A crew of 12 work the "white mine" in the Santa Rita Mountains round the clock, seven days a week, to produce about 100,000 tons a year of limestone, also known as calcium carbonate.

That translates into 20 truck loads of limestone a day that come down the mountain from the mine, destined to become either part of "pool mix" used to coat swimming pools, or as a filler in paint, or to make drywall.
Other uses include athletic field markings, fire retardant for clothing, landscape or aquarium rock, or an additive to cattle, chicken and pig feed.

The large veins of limestone, which have a distinctive white appearance on the northwest slopes of the Santa Ritas, are due to an ancient deposit of marine shellfish and fossils.
Given the right geologic conditions, the limestone could have become marble.