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"Kinradite": Orbicular Jasper from San Francisco

Last Updated: 11th Dec 2008

By Daniel Russell

Notes On “Kinradite”:


A Variety of Orbicular Jasper from San Francisco, California
By Daniel E. Russell



“The variously marked and colored jaspers of the San Francisco region, especially the "kinradite" variety, are meeting with increasing appreciation in that city and among tourists…”– Sterrett, 1913


“Kinradite” was a trade name adopted circa 1910 for a jasper containing spherules of quartz colored deep to light (almost colorless) red by microscopic inclusions, that was being commercially exploited in the San Francisco region of California.

Sterrett (1911) states that the jasper was “discovered about 30 years ago” (circa 1880) by J J Kinrade, a professional lapidary in San Francisco. The principal localities for the material which Kinrade identified were at a point one mile south of Sausalito in Marin County (near Fort Baker in Golden Gate National Recreational Area), westerly along the coast to Point Bonito, and at Lands End in what is today Lincoln Park west of the southern end of the Golden Gate Bridge, San Francisco County. Kinrade reported to the United States Geological Survey that similar orbicular jasper has been discovered at scattered points along the California coast as far north as the Oregon border. The best material came from the area between Fort Baker and Point Bonita.

Kinradite Localities, San Francisco Area
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The material found near Lands End was associated with a highly altered igneous rock, sandstone, and serpentine, which Waldemar T Schaller interpreted to be part of the Franciscan formation. The specimens recovered from the site south of Sausalito were also associated with sandstone as well as basalt, diabase, sandstone and radiolarian chert which Schaller also believed was a component of the Franciscan formation. The orbicular jasper occurred as lenticular inclusions in the basalt and diabase. Liberated from the basalt by wave action, the jasper formed pebbles and cobbles on the shoreline.

In gross appearance, “kinradite” consisted of a ground-mass of red, brown, or green jasper containing inclusions of red spherules of quartz. Sterrett (1912) stated that “most common type of stone consists of bright-red spherulites in dark-greenish and reddish-brown matrix.” The spherules varied in size from microscopic to over 2.5cm in diameter, with the preponderance of them readily visible to the naked eye. The material exhibited signs of brecciation, with bulk specimens exhibiting fragments of assorted colors of orbicular jasper, jasper devoid of spherules, and fragments of a “green rock” that was not adequately characterized. Sterrett (1911) stated that he believed the “green rock” was “composed of more than one mineral” and resembled epidote. The “green rock” sometimes also exhibited a spherulitic texture, which in part had “the texture of chlorastrolite, but has not been identified as that mineral” (chlorastrolite is an obsolete term for Pumpellyite-Mg; it not been observed in the area).
The spherulites have a radial structure with concentric bandings around the center. The centers more commonly are bright red and are surrounded by one or more layers of lighter red. The outer portion of the spherulites is less strongly colored and exhibits the fibrous radial texture plainly. Green, brown, gray, and black fragments and streaks compose the remainder of the rock. The whole has been fractured and cemented together again, even the spherulites, many of which show stars, with throe to seven or more rays filled with lighter-colored mineral, in their centers. Pebbles and fragments of jasper-like red quartz similar to the spherulite rock, but without such striking texture, are found with the spherulitic rock. Sterrett (1911)
Similar material, composed of an ochre-yellow jasper containing spherules of red quartz were also recovered and cut from the area around Bonita Point, Marin County.
In thin section under the microscope the spherulites present all the appearances of chalcedony but, unlike that mineral, have a positive elongation characteristic of quartz. They are composed of radiated fibers, and between crossed nichols give a dark cross extinction which reacts positively when tested with the gypsum plate. The pigment of the spherulites is seen to be a red dust, apparently hematite, generally arranged in layers with concentric structure. The starlike fractures in the spherulites resemble shrinkage cracks and are filled with fibrous to granular quartz which incloses practically no hematite. The quartz stars are in many cases connected with seams of quartz ramifying through the rock.
Schaller undertook a chemical analysis of “kinradite” (apparently from a specimen collected at lands End) and found that it 88.5% SiO2 and 10.3% Fe2O3. He noted that the Lands End material contained grains of hematite to more than a 1 mm in width, but that the “kinradite” from south of Sausalito contained less hematite.

In 1915, Schaller stated that “a large production of kinradite from California is reported.”

Summarizing the potential of “kinradite”, Sterrett commented that it “polishes well and is very handsome. The variety of patterns and colors and the extreme beauty of the spherulites when examined closely render the stone attractive. It would serve well for small ornamental objects, as inkstands and
paper weights, and some is quite pretty enough for use in jewelry. It could be used in the same way as jasper and strongly colored agates.” In retrospect, however, it is unlikely that the supply of “kinradite” would have been adequate to raise it above the level of a novelty gem material for the local tourism market.

The life of J J Kinrade appears to be poorly documented. At least part of his career as a lapidary was spent at 628 Montgomery Street, the historic “Montgomery Block” or “Monkey Block” building which was the first fire- and earthquake-proof building in San Fransisco, and which attracted a cadre of literary illuminati that included Mark Twain, Bret Harte, Jack London and Ambrose Bierce. Francis J. Sperisen (1961) who had known Kinrade recalled that he “worked exclusively in cabochon stones (and) did all his work including sawing of large stones on a hand-driven machine.” In a nation-wide census of companies and individuals involved in commercial gem production in the United States during the period 1917 to 1919, Kinrade reported that he specialized in “Copper ore gems”, Quartz, Lapis lazuli, Rhodonite, Topaz, Turquoise, Olivine, Tourmaline, Opal, Variscite, and Vesuvianite.

Kinrade was apparently also a mineral and fossil collector (possibly a mineral dealer as well??), and on several occasions donated specimens to museums in Milwaukee, Chicago, and San Francisco.

In addition to “kinradite”, J J Kinrade also brought to the market-place a lilac colored pyroxene in a grey-green rock. The pyroxene was identified as diopside by Esper S Larsen and George Stieger, which Kinrade and others had initially believed to be wollastonite. This material was also found in the San Francisco area although details are lacking. The material took a “good polish”. (Sterrett, 1911) Kinrade was also instrumental in bringing plumasite, a rock consisting of pale violet blue corundum and oligoclase, to the attention of Andrew C Lawson about 1902. Kinrade has received the rock, either as a potential lapidary material or as an intriguing mineral specimen, from J A Edman of the Diadem Mine in Plumas County, California.

Specimens of cabochons of “kinradite” were enshrined in the Smithsonian Institute's gem collection. Merrill noted that at least 13 cut examples were archived in the National Museum:
CHALCEDONY JASPER var. KINRADITE San Francisco, California.
Twelve gems, cabochon, elliptical and circular girdles; mottled red, gray, and green; total weight, 47.6 carats; 21 by 9 by 5 to 8 by 4 mm. Cut from specimen 87422 No. 1534

CHALCEDONY (JASPER var. KINRADITE San Francisco, California. Cabochon, elliptical girdle; red and light brown; 13.7 carats; 25 by 14 by 6mm . Cut from specimen 87422 No. 1535

The proposal to name the jasper “kinradite” was put forward by four San Franciscans, Harry C. Catlin, John C. Catlin, Thomas R. Craigie, and Alfred Galpin, “in acknowledgement of Mr. Kinrade's services in exploiting a gem of interest to both the local and the tourist trade of California.” The two Catlin brothers were sons of Amos Catlin, a pioneer California attorney who had come to California in search of gold in 1849 and stayed to become a prominent judge. Both Harry and John Catlin had established successful law practices in San Francisco, with offices in the building at 628 Montgomery Street; Harry Catlin additional was a columnist for the San Francisco Chronicle. Thomas R. Craigie was a staff member of the United States Customs Service in San Francisco. Alfred Galpin was a sculptor and graphic designer who was on the staff of the San Francisco Chronicle and later served as editor of the Standard Oil Bulletin of San Francisco. (Sterrett describes the four as “gentlemen interested in an amateur way in native gems.”)


Bibliography

Lawson, Andrew C
Plumasite an Oligoclase-Corundum Rock Near Spanish Peak, California
Bulletin of the Department of Geology (University of California) Vol. 3, No. 8, pp. 219-229

Merrill, George P
Handbook And Descriptive Catalog of the Collections of Gems and Precious Stones in the United States National Museum Smithsonian Museum Bulletin 118, Washington DC 1922

Schaller, Waldemar T “Gems and Precious Stones”
in Mineral Resources of the United States, Calendar Year 1915
Washington DC 1917

Sperisen, Francis J
The Art of the Lapidary
Milwaukee, USA, Bruce Publishing Company 1961

Sterrett, Robert B “Gems and Precious Stones”
in Mineral Resources of the United States, Calendar Year 1910
Washington DC 1911

Sterrett, Robert B “Gems and Precious Stones”
in Mineral Resources of the United States, Calendar Year 1911
Washington DC 1912

Sterrett, Robert B “Gems and Precious Stones”
in Mineral Resources of the United States, Calendar Year 1912
Washington DC 1913

Stoddard, B H “Gems and Precious Stones”
in Loughlin, G F Mineral Resources of the United States, 1919
Washington DC 1922





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