Mineral Of The Day #164: Hedenbergite
Mohs Hardness Scale: 5½ - 6½
Category: Pyroxene mineral
- It is found primarily in metamorphic rocks!
- It was named in 1819 by Jöns Jakob Berzelius in honor of Mr. Anders Ludvig (Ludwig) Hedenberg. He was formerly a clerk associated with Mountain College, and later chemistry student and co-worker with Berzelius and who first described the mineral.
We have A LOT of heulandite specimens.
Are any of them inferior? They could be candidates for deaccessioning. Or are all of them good?
Well, I'm not the biggest FAN of zeolites, so...
Rocks and minerals are fine introductions to the study of natural history and to a greater appreciation of nature, because they are tangible and often beautiful objects that can be preserved in collections. They do not fade and lose their beauty, like flowers; making a collection of them harms no living thing. Unlike many other objects of nature that may be arranged in collections, their preservation actually conserves them for future generations.
Frederick H. Pough, A Field Guide to Rocks and Minerals.
Mineral Of The Day #163: Stibnite (Revisited)
Mohs Hardness Scale: 2
Category: Sulfide mineral
This specimen of stibnite is quite spectacular, and we are dedicating it to our dear friend Beth who is retiring after 16.5 years of dedicated service to the Brooklyn Children’s Museum. Best wishes from the Mineral Of The Day Team!
- Historically, pastes of stibnite and fat materials have been used since 3000 BC as eye cosmetics called kohl in the Middle East.
- Stibnite is most commonly pulverized and heated to extract the antimony and make flame retardants and engine bearings.
- It is also used in making fireworks (Happy Fourth of July!).
Diamonds, they’re very interesting. They have many facets.
Mineral Of The Day #162: Triphylite
Mohs Hardness Scale: 4-5
Category: Phosphate mineral
Formula: Li(Fe, Mn)PO4
- Triphylite is used as a source of lithium and phosphorus.
- It is a rather scarce phosphate mineral.
- Its name in Greek means “family of three” which probably refers to the three ions: iron, lithium, and manganese.
- Triphylite is the primary mineral for many beautiful and unusual secondary minerals.
People will stare. Make it worth their while.
Harry Winston, 1896-1978, jeweler and owner of many legendary gemstones
Mineral Of The Day #161: Aventurine
Mohs Hardness Scale: 6.5
Category: Silicate mineral
- Aventurine ranges in color from green, peach, brown, blue and a creamy green. Besides its uses in jewelry, aventurine is also used for ornamental purposes like vases, bowls, and figurines.
- It is a form of quartz, characterized by its translucency. Inclusions of platy minerals give it a shimmering or glistening effect termed aventurescence.
- It is the Star Sign for Libra and the Planetary stone of Taurus.
- Main markets for aventurine are landscape stone, building stone, aquaria, monuments, and jewellery.
Happy Gemstone Thursday!
Mineral Of The Day #160: Laumontite
Mohs Hardness Scale: 4
Category: Tectosilicate mineral, zeolite group
- Laumontite is a common mineral, found worldwide. It can be locally abundant, forming seams and veins.
- It can be used as a chemical filter.
- It is popular with mineral collectors, but exposure to light causes a loss of water that can destabilize the crystals and cause them to become powdery.
A beautiful description of laumontite from galleries.com:
Laumontite is a handsome mineral. Its columnar crystals can project above the clutter of crystals at its base and appear like a monument above a desert plain. Its crystals can also form smaller, almost acicular jutting prisms that look like a rugged landscape. Although specimens are usually opaque, it retains an alabaster-like luster reminiscent of carved sculpture.
Mineral Of The Day #159: Moonstone
Mohs Hardness Scale: 6
Category: Silicate mineral, feldspar group
- Moonstone gets its name from a visual effect or sheen caused by light reflecting internally in the moonstone from layer inclusions of different feldspars.
- Adularescense is the term for moonstone’s shimmer that always looks different when the stone is moved.
- It has been used for jewelry for centuries, including by ancient civilizations!
- In modern times, moonstone was popular as part of the Art Nouveau movement, but its usage waned by the mid-1920s.
- In India it is regarded as a holy and magical gemstone.
- In Arabic countries, it is a symbol of fertility.