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Can shells become agate? They are very opaque. There are a few different examples I found outside of Payson AZ on a pull out by hwy 87

Hello, wondering if this is a fossilized sea sponge or coral? It is large and quite heavy. Found in the Coconino forest past Payson and Strawberry.

Hello, apologies for opening a new thread. Are these just neat looking rocks or possible fossils? I could not tell.

Hello, Over the years I have found several fossilized shells on the Mogollon Rim in Arizona. I was wondering if these can be identified?

Rediscovered this interesting piece while doing some deep cleaning today! Found this in Northern Arizona, on the Mogollon Rim. I am very new to fossils, not a huge enthusiast but I love collecting interesting rocks and things that I find camping. Does anyone know what this is? Not sure if you can tell from the pictures, but it's sparkly, too.

Fossils From The Old Timers Control Road Locality By Arizona Chris A while back, while skimming through a short booklet on the Pine area of the Mogollon Rim in northern Arizona where we live, I came across a paragraph stating: "And while your in the vicinity, be sure to visit the ancient marine beds that Old Timers used to collect fossil shellfish from". The location given was the intersection of Highway 87 and Control Road 64 north of Payson, Arizona. The next weekend, we drove up to the site, to see these "fossil shellfish" for ourselves. As you turn off the highway onto the dirt control road, you cross a cattle guard and there is a dirt pull off on the north side of the road, only a hundred feet or so from the main highway. You are at the foot of a small ridge which is grown over with junipers, pinyon pines, and scrub brush. It is on the slope of this ridge and all along it you will find limestone with piles of red chert rubble among the pines. This is where most of the fossils are, in the chert rubble. After a few hours of searching, we found Composita and Spiriferer brachiopods, numerous crinoid stems with beautiful star shaped central holes, several spaghetti like bryozoans and a host of perfectly preserved gastropods. There were also some surprises too, which I'll get to later! The presence of brachiopods that were identical to those picked up at the Pennsylvanian Naco limestone near Khols Ranch strongly suggests that this site is also Naco as well. But here we find some additional fauna representative of a shallow water marine environment. Further examination of the area revealed that calcified and silicified fossils were also in the surrounding limestones, but less concentrated than the chert rubble. I found it easy to dissolve out many of the specimens with acetic acid (vinegar) or dilluted Muriatic with many of them excellently preserved in the protective limestone. Descriptions of Fauna present Brachiopods: Three basic brachs were seen, the best preserved specimens were under one inch in size. The smallest and by far the most common were the Composita subtilita, a small typically 1/2 inch sized brach with a relatively large and clearly visible pedicle opening, and a nicely symmetrical shell. Second most abundant were the Spirifer type brachiopods, typically calcified in the limestone, and difficult to remove since calcite and limestone both dissolve in the acetic acid. These "bat wing" shaped invertebrates are best removed by mechanical preparation methods such as small chisels and ice picks. Most were less than on inch in size. Least abundant, but by far the largest brachs found were a species very similar to the Antiquatonia sp. productids found in the Naco at Khols Ranch. Usually found incomplete or poorly preserved, these 1 to 2 inch brachs are covered with short spines or bumps on the surface, and are very deep bodied - almost spherical in shape for complete specimens. Many of them were encased in a red cherty material making them easy to spot on the ground. Gastropods: One large species of gastropod can also be found at this site. Resembling a horn or trumpet, this one inch thin walled Platyceratid is usually found fragmented, or missing portions of the whorl or aperture. A complete specimen from this site would be a prized find. The one I found was about an inch long. Platyceratids live permanently fixed to crinoid anal tubes and are coprophagus. (read: Poop sucker) Sponges: A 2 - 4 inch diameter discoidal sponge can be found here. The most common type is found primarily on the slope near the parking location weathering out of the hill. Always fragmented, this net flat sponge is preserved as a 3/8 inch slab of red chert in sizes up to several inches across. The net like impressions are always on both sides of the small slabs, and by looking at the side view of the pieces internal structure is clearly seen. This thick three dimensional preservation of such animals is unusual, as most fossilized remains of sponges is nearly always a surface impression. Bryozoans: A common type of bryozoan found here appears as a crust on some of the limestones. Resembling very small strands of tangled bits of "angel hair" pasta, this delicate invertabrate is rewarding under a stereo microscope with its delicate details. Corals: Two varieties of coral are present at this site. Both are rugose corals, the most common type a small horn coral ranging from 1/2 inch to 2 inches in length. They are usually found as silica fied casts in the chert rubble piles. Also seen were some poorly persevered corals I have not been able to specifically identify due to their fragmentary nature that resemble inch or two long irregular cylinders in shape. A good specimen here would also be a prize find. Enchinoderms: Found primarily as stems, and a few dissaccociated fragments, the crinoids are well represented in this fauna. Two species are found, a larger columnal segment resembling "Cheerios" in appearance with a beautiful central canal shaped like a rounded five point star. These can be found in the cherty matrix or as separate casts in the rubble piles. A second Smaller type with a small round central canal is also quite abundant and is seen in the cherty matrix and limestone as calcified casts. Finally, the surprise as promised. Also commonly found among the chert rubble remains are what possibly appears to be pieces of petrified plant material. Burrows / Trace Fossils: Resembling limb casts or sections of roots, these inch or two long pieces have an exterior very much like bark, and a cross section with concentric details simiar with the usual variety of petrified wood - we thought at first. Or to be some poorly preserved bryozoan or coral. But after finding many perfectly preserved specimens varying in diameter from 1/2 to 1 1/2 inches, it seems more convincing that these originate from shrimp or arthropod burrows. The walls show very distinct scratch marks from their digging action and are actually quite attractive finds. Perhaps if you visit this site, you can find some of this unusual material and decide for yourself! Photos of the material: 1. Red Cherty Limestone 2. Chert coated crinoid oscicles 3. Large rugose horn corals 4. Pancake Sponges 5. 1/4 of a large Pancake Sponge 6. Platyceratid Gastropods 7. Productid Antiquatonia sp. 8. Anthroacospirifer and Composita Brachiopods 9. Red chert filled burrows / Trace fossils 10. Eiomocrinus sp. Crinoid - Infra Basal Calyx plates 11. Eiomocrinus sp.Crinoid - Basal Plates from Calyx 12. Eiomocrinus sp.Crinoid - Armor Spikes from Calyx 13. Syringopora - Tabulate Coral

This looks like a fossilized egg in basalt or other rock but the pics I've seen of fossil eggs look brown. This is white and rock hard. I found it near the eastern end of the Mogollon rim in Arizona. Can anyone ID it?