moqui marbles, utah Iron oxide concretions (Moqui marbles) Moqui Marbles, hematite concretions, from the Navajo Sandstone of southeast Utah. Scale cube, with "W", is one centimeter square. The Navajo Sandstone is also well known among rockhounds for its hundreds of thousands of iron oxide concretions
Watermelon tourmaline. Tourmaline is a crystal boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classified as a semi-precious stone and the gemstone comes in a wide variety of colors. The name comes from the Sinhalese word "Thuramali" or "Thoramalli", derived from different gemstones found in Sri Lanka. [Wikipedia]
Musgravite 35K a carat. Musgravite is one of the newest and most rare gemstones in the world. Musgravite is a silicate mineral whose main ingredients are beryllium (Be), magnesium (Mg) and aluminum (Al). It was named ‘musgravite’ after the area Musgrave in Australia from where the material was first found. The musgravite was later found also in Greenland and Madagascar, but neither of them produces gem quality material.