The Meteoritical Bulletin Database tells us that Gladstone (stone) is 57.3 kg of H4 found in New Mexico in 1936. A little digging unearthed more information. (There is a Gladstone (iron) found in Australia in 1915).
Lang and Keil wrote the guidebook Meteorites of Northeastern New Mexico in 1976 in which they noted:
Having had some success in northeastern New Mexico, Nininger sent one of the helpers to Gladstone (Nininger and Nininger, 1950):
“In 1936 we undertook to prove the hypothesis that meteorites have fallen on all areas of the earth recently enough to be yet recognizable. We sent Mr. and Mrs. Alex Richards to Gladstone, New Mexico, with instructions to stay three weeks exhibiting specimens and providing information as to their importance and how to distinguish meteorites from other rocks. We had no information or hint of any kind that meteorites were present in that area. The first two weeks brought nothing to light, but during the third week six stones were recovered aggregating 183 pounds and representing three distinct falls, namely, Gladstone, Farley and Ute Creek, all within six miles of the Gladstone post office.”
Three of these stones were named after Gladstone.
Gladstone was classified as an H6 chondrite by Van Schmus and Wood (1967) and as an H4 by Levi-Donati and Jarosewich (1974).
Later Gladstone was assigned a shock value of 3 and its brecciated texture recognized. It was found to be gas rich and hence regolith – the surface soil of an asteroid exposed to the sun and space.

Slice of Gladstone 27 cm long displaying both fine and coarse metal. Photo courtesy of Michael Farmer.

The same slice showing light brown clasts in a dark grey matrix. Photo courtesy of Michael Farmer.

Closer, a 10 cm wide view. Photo courtesy of Michael Farmer.

Thin section made from a different slice of the same stone made by Arizona State University (ASU) viewed in transmitted light. Sample is 42 mm long and brecciation is apparent at this scale too.

Dark and light lithologies in plane polarized light and incident light. Metal appears silver-blue. Field of view is 5.2 mm wide.

Same view in cross-polarized light (XPL).

Light and dark lithologies in plane polarized light and incident light. Metal appears silver-blue. Field of view is 5.2 mm wide.

Same view in XPL.

Another ASU thin section viewed in transmitted light. Sample length at top is 35 mm. The dark inclusion is impact melt rock (IMR) similar to that found in NWA 869 L3-6, another regolith breccia.

The fine grain IMR in XPL. Clast is 8.5 mm top to bottom.

Detail of lower left IMR clast. FOV=3 mm.

Detail of upper right IMR clast. FOV=3 mm.