Orthoceras Nautiloid

Related to modern day squid and octopus, the Orthoceras is an ancient cephalopod that lived in the Paleozoic Era, during the Ordovician period around 480 million years ago. Orthoceras fossils are quite abundant and a popular choice for necklaces, pendants, and decorations. This particular polished specimen was found at a local fossil emporium and caught our attention right away. Contrasting marbleized white shell and black stone emphasizes detail of the cephalopod structure which certainly catches the eye.

Additionally, the Nautilaidea Orthoceras is named for having a shell as straight as a horn, which is sometimes another attractive quality in jewelry design. It's understandable to see how one might see the suture lines as something similar to how an exotic plant stalk or leaf might fossilize, yet the narrowing tube shape displays a distinct three-dimensional tube especially when examining the thinnest portion. The black and white fossil has light marble features in the base rock that are likely fragments from other cephalopods fossilized at the time.

We hope the description of characteristics and features of the Orthoceras helps others identify this fossil in a collection. Holding onto an ancient rock that was once a creature living almost 500 million years ago is difficult to believe it's really so old, but to us this is part of the thrill and excitement hunting for fossils and learning about their origins in the timeline of Earth's history.

Raw Emerald

Mining in the United States for precious gems can be a fun and rewarding experience, especially when it comes to learning about mineral formations. One gemstone in particular, the emerald, is sought after for both rarity and beauty. The rare aspect is dual-fold, in that concentrations of emeralds are not very common, but also because finding facet-quality emeralds is even more rare. For example, the raw emerald specimen from North Carolina pictured here demonstrates how the formation can be a limiting factor in the size of emerald crystals.

Emeralds are a possible byproduct of hydrothermal processes when conditions and chemical composition are optimal. The way to envision this is to imagine hydrothermal fluids under extreme pressure being forced to the surface and pushed through rock cavities by water or magma. When the catalyst recedes, hydrothermal fluids are left in the rock cavities to cool and form emerald crystals. Emeralds created under these conditions in crevices and rock fractures, which means jagged fractures largely determine the size of emeralds formed.

Clarity is another factor in the rarity of emeralds. The deposits might be in proximity to calcite and other minerals which may cloud the hydrothermal fluid. This specimen demonstrates a ratio of clarity, where the majority of emerald crystal is foggy and opaque, while only a small fraction is clear enough to allow light to pass. Stripe patterns from internal crystal fractures are visible throughout the crystal material. Emerald can be surprisingly fragile and it's possible cracks in the crystal are the result of increased pressure or rapid cooling during the solidification phase.

The specimen also reveals how the shape of rock cavities and fractures play a role in the formation of emerald crystals. Edges of this crystal have been rounded and slightly polished to reduce further chipping or fracturing when handled as a demonstration piece. The monetary value of the specimen is quite low without a complete raw formation and the lack of sizeable pieces with clarity for faceting, but it is still a beautiful gemstone to have in the collection.

Raw Copper

While hiking along Lake Michigan's eastern shoreline, we happened upon a very interesting specimen of what appears to be raw copper complete with teal oxidation. The rock had tumbled up the beach from wave action and caught the eye almost immediately. Light bluish teal and copper colored flecks dot the outside of the rock on both sides. One side contains more areas of oxidation and larger pitted cavities where the copper meets the surface.

The opposite side features small pits with copper flecks shining through on its surface. Round, crater-like holes, likely from weathering erosion effectively cover this side. Dots of copper are found among these tiny craters. The surface also developed a bit of sheen from tumbling in the waves with smaller rocks. After searching the area thoroughly, no similar rocks, fragments, or gemstones were found in the vicinity.


Though copper isn't often sought after by rock hounds, it's still a great to add to a general collection. Plus there is a distinct possibility of locating precious gems in the same area as copper deposits. Interestingly enough, we did want to find a piece of copper in a natural setting, however a specimen washed up on the beach is some distance away from the concentration. In fact this rock could have been part of a payload crossing the lake at some point. Either way we are happy to include this specimen in our collection, possibly as a stone to slice open for further analysis in the future.

Montana Sapphires

The first time traveling through Montana was quite the experience on a number of levels. We definitely understand why it is often referred to as Big Sky Country and it did not disappoint. Our goal was to tour around, explore a little, and look for gemstones. Since we were first time travelers, sticking to areas where the public is welcome is a must. Brooks and streams which could contain gems are plentiful, but many reside on private land and require permission from the land owners.

After some research and driving around, we discovered Gem Mountain in Philipsburg, Montana. It's easy to feel whisked away from the rest of the world, a getaway in your own little mountain town, in the quaint town of Philipsburg. The stay here is refreshing, and motivational, knowing there's beautiful scenery all around you, and that you're only a short drive away from an active sapphire mine nestled in the mountains.

We spent an entire day panning through tailings brought down from Gem Mountain. By mid-morning we really had a handle on the techniques taught by mine operators and were finding sapphire after sapphire in the load. At the end of the day we extracted more than enough raw sapphires to cover the day's mining expenses. A decent portion of the raw could be cut for jewelry, and there were even a few nice flawless specimens. Firing and hardening can be done right at the mines for a fee, but we decided to keep the stones raw.


Overall, the experience panning for sapphires in Montana is one well worth the time and effort. In a way it's amazing to think some of these old gem mines are still producing significant amounts of raw material on a daily basis. As awesome and educational as panning through tailings is, the next trip calls for a more adventurous experience on our own, now that we have a pretty good idea of what to look for.