TTHE MINERAL INDUSTRY OF HAWAII 255 
 
and flower pots. After acquiring the plant in 1966, the operating company
improved the equipment and production methods and reported an increase in
output and sales. 
 
 Gem Stones.—A large quantity of black coral gem material was collected
by scuba divers working off sainpans anchored to ledges in deep channel waters
off Lahaina, Maui Island. The divers made descents of nearly 200 feet, collected
and tied the coral trees to the anchor chain, and raised the anchor and the
day's find by filling plastic bags with air from the scuba tanks. Several
hundred pounds of gem-quality pink coral, was gathered off Oahu by fishermen
who dragged nets along the ocean floor. Lapidaries and jewelers near tourist
destination areas cut, polished, and mounted the black and pink coral in
rings, brooches, and earrings. 
 
 Limc.—Total production of quicklime and hydrated lime declined from
9,700 tons in 1966 to 8,250 tons in 1967, owing to decreased demands by sugar
mills and by the building trade. Sugar mills consumed 75 percent of the total
output in clarifying cane juice. Other outlets for lime were for water purification,
sewage treatment, and steel flux. Lime was produced at two plants; both operated
a rotary kiln and a continuous hydrator. Purchased limestone was used at
the Waianae plant on Oahu, and coral beach sand was. used as raw material
at the Lower Paia lime plant on Maui. 
 
 Pumice and Volcanic Cinders.—Production of pumice and volcanic cinders
totaled 290,000 tons. About 60 percent was used for construction and maintenance
of tertiary roads, primarily on the 
- island of Hawaii. The remainder was prepared for use as lightweight concrete
aggregate, as roofing granules, and in decorative landscaping. Output of
volcanic cinders on Hawaii Island came from deposits near Pepeekeo, Keaau,
Pahoa, Pahala, Naalehu, and Kamuela. Cinders were produced near Koloa, Eleele,
and Kaumakani on Kauai; at Olowalu, Lahaina, and Honokohau on Maui; and near
Kaunakakai on Molokai. Lightweight concrete aggregate, for use on Oahu, was
supplied from a pumice quarry at Puuwaawaa on Hawaii Island. 
 and from a volcanic cinder deposit at Waieli on the island of Molokai. 
 
 Salt.—Crude salt was produced at a small commercial facility near
the Barbers Point barge harbor on Oahu. Sea water was pumped to a distillation
unit and the brine was solar-evaporated in ponds and also artificially evaporated
in wood-fired kettles and pans. On Kauai, an association of native families
produced salt for its own use on the saline mud flat near the old Port Allen
airport. Brackish water from shallow wells was scooped into mud-lined ponds
to produce salt by solar evaporation. The coarse crystals of salt produced
in Hawaii were used in drying fish and seasoning meats. 
 
 Sand and Gravel.—Sand comprised the major portion of the 469,000 tons
of sand and gravel produced in 1967. Principal production of sand occurred
on Molokai at Papohaku Beach. The sand was trucked to Lono Harbor and barged
to Oahu for use in concrete and concrete products. Appreciable tonnages of
sand from beach, dune, and streambed deposits was produced at Maili on Oahu;
Kealia, Kapaa, and Bonham on Kauai; near Kaanapali, Kahului, and Wailuku
on Maui; at Moomomi on Molokai; and at Polihua on Lanai. Coral sand from
the beach near Lower Paia on Maui was calcined to produce lime. Alluvial
gravels were mined from the foothills near Waikapu on Maui for local use
as base material and concrete aggregate. 
 
 Stone — Stone producers quarried 2,624,000 tons of basalt, 921,000
tons of coral limestone, and 555,000 tons of miscellaneous stone. The total
output of 4.1 million tons was nearly 1 million tons less than that of 1966.
Nearly 75 percent of the volume was produced on Oahu, 18 percent on Hawaii,
and 7 percent on Kauai, Lanai, Maui, and Mobkai. The quantity processed for
use as concrete aggregate and base material amounted to 3.6 million tons,
compared with 4.5 million tons in 1966. 
 Basalt rock was quarried at Kaena, Kapaa, Halawa, and Palailai on Oahu;
at Hibo and near Kona on Hawaii; near Puhi on Kauai; at Camp 10 on Maui;
and at Manawainui on Molokai. Coral limestone was produced primarily at Barbers
Point, Lualualei, Waimanalo, and in the