More information is provided by NAU American Southwest Virtual Museum

Sweetwater Red-on-gray is an earlier type of Hohokam Buff Ware primarily located in the Gila River valley south of Tucson. 

Archaeological Culture: Hohokam

Date Range: ca. A.D. 600-650.

Construction: By paddle and anvil.

Firing: In a neutral to oxidizing atmosphere; fire clouds common.

Temper: Course-grained mica schist and quartz.

Surface Finish: Muscovite mica is plainly visible on vessel surfaces, and more so on polished vessels; non-porous; not slipped.

Paste Color: Beige, gray, or brown; dense.

Forms: Bowls, jars, censers, scoops, few effigies.

Decoration:

• Paint: Bright red, dull red, or purplish red; occasionally smeared by polishing; always brush-painted.


• Pigments: Iron oxide mineral paint.


• Design: Banded layouts; straight-line hachure bands that later become cuneiform; cross-banded; simple band open “star” (bowl only; large hachure-filled triangular spaces pendant from rim with no additional interior design); sectioned layouts with hachured “star;” quartered; opened quartered; all-over layouts with curvilinear scrolls, commas, two-ring concentric circles, and curvilinear spirals; composite layouts with spirals and radiating lines; Queen Creek variant (early) lacks hachure-fill; most rims are not painted; trailing lines are absent.


• Incising: Deep, regular incising that is often complicatedly patterned; coil-based incising.

Key Traits: Gray or brown paste, fire clouding, and minimal polishing with a micaceous sheen; spacing of hachure lines is generally equal to or greater than the thickness of the lines; thickest lines are less than 4 mm wide.

Comparisons: Estrella Red-on-gray had wider lines and less elaborate designs; Sweetwater Red-on-Gray is never red slipped/washed, generally lacks incising, and had brush-painted designs. Early Snaketown Red-on-buff is more complex; some hachure-filled designs are indistinguishable between the two types, but the line work on Sweetwater vessels is more variable and less controlled; incising on Sweetwater vessels is deep and regular; on early Snaketown vessels, incising is shallow and irregular. Hatching lines on late Snaketown Red-on-buff are finer and more closely spaced. Hatchure and curvilinear designs distinguish Sweetwater Red-on-gray from other contemporaneous Southwest red-on-brown types.