Meckley's Quarry

Meckley's Quarry is located in Mandata, Northumberland County, Pennsylvania, USA, at coordinates 40° 40' 24'' North, 76° 50' 9'' West. This places it in the northeastern United States, surrounded by rolling hills and small towns like Herndon (4 km), Port Trevorton (4.5 km), and Pillow (4.6 km). The region is known for its agricultural landscapes and is part of a broader area with other mineral localities, including the historic Blackstone Mill in Pillow, which connects to the local rockhounding community.

The quarry is renowned for its celestine (strontium sulfate) crystals, available in striking blue and yellow, highly sought after by collectors for their size and quality. Other minerals include calcite (milky white or transparent yellow prisms), fluorite (dark purple, massive, or small octahedrons), gypsum, sphalerite (bright orange, flaky, uncommon since 2003), and strontianite (white, crystalline mats with fluorescence under shortwave UV light). These unique occurrences make it a treasure trove for enthusiasts.

Meckley's Quarry exposes laminated Tonoloway Limestone, a sedimentary rock from the Silurian period, formed in ancient tidal flats. The rock shows layers of algal mats and mud cracks, indicating a dynamic environment of shallow seas and periodic exposure, which contributed to the formation of its rich mineral deposits, especially celestine.

Established in 1936 by J. Eugene Meckley on a 246-acre site, the quarry initially produced agricultural lime using eight "set kilns." It expanded over the years, adding truck and field spreading in 1946, a grinding mill in 1947, and was approved for road construction materials in 1963. In 1982, it was tested for sulfur dioxide capture, proving effective. Owned by the Meckley family for three generations until 1991, it remains active today, focusing on industrial and agricultural materials.

The quarry is a hub for the rockhounding community, with the Central Pennsylvania Rock and Mineral Club (45 km away in Harrisburg) organizing annual collecting events, typically in late August or September. These gatherings, including picnics at Ted and Holly Keck's historic Blackstone Mill in Pillow, foster a sense of camaraderie. Notable figures like Kerry Matt and John "Pen" Ambler enhance the educational and social aspects, making it a cultural landmark for mineral enthusiasts.

Northumberland County has a humid continental climate with cold winters (January–February, often snowy) and warm summers (June–August, temperatures in the 80s°F). The most pleasant months are June, August, and September. The quarry is set in a landscape once heavily forested, now including agricultural fields and small towns, with deciduous forests and streams nearby. The temperate climate supports diverse flora and fauna, though quarry operations likely impact local ecology.