These Carbonates have Chemistry.
Calcite, a calcium carbonate, is the most common of the carbonates. We admire its lovely crystal forms—all 600 of them. We also use it in huge quantities in its massive form, limestone.
Dolomite, a calcium, magnesium carbonate, is not as common as calcite. It also forms in lovely crystals, but not in as wide a variety as calcite. We also use dolomite in its massive form, dolostone. Which brings up two questions: “How do we distinguish calcite from dolomite?” and “How do we distinguish between limestone and dolostone?”
The first question is relatively easy to answer. Dolomite never forms in scalenohedral, or “dogtooth”, crystals, which is one of the common forms of calcite. Also, calcite forms flat, rhomboid “poker chip” crystals, but dolomite does not. Calcite responds vigorously to acid, while dolomite responds less vigorously. Calcite is 3 on the Mohs Scale of Hardness, but dolomite is Mohs 4-4.5. One other difference you may see is the smoothness of the crystal faces on your specimen. Dolomite crystals, because of an unusual internal structure, may have slightly curved crystal faces, while calcite does not. These are some simple tests you can use to determine the identity of a carbonate you own.
Denne historien er fra April 2017-utgaven av Rock&Gem Magazine.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent ? Logg på
Denne historien er fra April 2017-utgaven av Rock&Gem Magazine.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent? Logg på
This News is for the Birds
The amazing range of the would-be birds!
CALIFORNIA MAGNESITE PLASMA AGATE
California magnesite plasma agate is a kaleidoscope of minerals. Much like its neighbor from Clear Creek, it contains chalcedony, serpentine, jadeite and chromite.
HOW TO CREATE A CABBING MATERIAL
Even though Mother Nature creates almost unbounded types and numbers of beautiful materials for cabbing, often I struggle to find a slab that will work for the project that I want to do.
PINWHEEL - VIET GEMS 149
I am frequently asked what my favorite gemstone designs are and where to find them. After my trip to the Tucson Gem and Mineral Show, I updated my list of favorites to include gemstone designer, Phan Thanh Trung.
Copper Minerals: My Favorite
I have lived in the “Copper State” of Arizona for 65 years so it should not surprise readers that copper minerals are among my favorites to collect.
OPPENHEIMER, TRINITY SITE AND TRINITITE
The widely acclaimed, 2023 Hollywood biographical movie Oppenheimer recently won seven Academy Awards including Best Picture and Best Actor (Cillian Murphy).
Clearing ,Smudging & Setting Intentions for Stones
Why do you believe what you believe? Are your beliefs true because you choose to believe them? Whether it is religion, science or the metaphysical, your belief and faith make it real to you in mind, body and soul.
Rhode Island's Hobbit Stone Age
Rhode Island may be 22nd out of 30 states in miles of total coastline but when you compare coastline length to land acres, it ranks second only to Maryland.
Black Range Amethyst
Amethyst in Southwest New Mexico
EQUINE Bling!
How an Oklahoma Saddle Maker Uses Moissanite, Gold, Silver Turquoise tc to Adorn Saddles Jewelry