Manganocalcite
Gemstone Quality Standard
About Manganocalcite
Manganoan calcite or manganocalcite is a variety of calcite being rich in manganese, which gives the mineral a pink color.
The most fascinating thing about this stone is that it is fluorescent. Put under ultraviolet light the stone emits a strong purple/orange glow.
Important 2025 Update:
So far, there has been only one mine for manganocalcite in Peru. The manganocalcite vein was very thin (max 6 cm thick) and did only allow for small spheres and other objects.
Over the last couple of years, we noted the quality of the material getting worse and worse. It showed less fluorescence, more white chalky contents, holes, and black impurities as well as less good color. At the same time, the provider did increase prices constantly. All this is a clear sign of a mineral vein being fully exploited and disappearing.
Now we have good news. A new vein of manganocalcite was found in Peru providing top-quality material with super fluorescence, great banded color, without chalky parts or black impurities, and no porous material full of holes.
Rarity
There are only two mines in Peru.
Availability
We provice rough rock, preselected slabs of jewelry-grade material, decor pieces, cabochons and jewelry with manganocalcite
Color
Pale rose-colored, often banded.
Impurities
We recommend staying away from cheap brownish and cracked material. This should have never made it into cabochon production.
Fluorescence
Top-quality material turns bright orange under UV-light
Polishable
Manganocalcite can be olished to a glass finish.
Cutting Quality
Challenges:
Manganocalcite is soft and brittle and tends to chip on the edges and corners. It requires an experienced gem cutter to obtain high-quality cabs.
Top-cutting-quality is characterized by:
- a polished backside
- a sharp unchipped edge between the backside and the bezel
- a very straight and even highly polished bezel
- a sharp unchipped edge between the bezel and the dome
- a well-shaped dome, not showing any deformation
- Top-quality polish
Pricing
Adequate pricing must take into account the cost factors to obtain top-quality cabochons:
- Acquisition of top-grade Manganocalcite with strong color in the mine.
- Selection of material without impurities and discarding more than 50 percent of the rough rock as unsuitable for jewelry.
- A usual material loss of approximately 90 % of the selected material during the cutting and shaping process.
- The level of experience required by a cutter to produce a flawlessly shaped and highly polished cabochon from such a soft material.
- Market research
- Our Jewelry Grade (A)
- Our Top-Quality Jewelry Grade (AA)
- Our Premium Jewelry Grade (AAA)
The data in this sheet has been compiled by reviewing a great number of websites and sales platforms.
Material quality:
We can find all kinds of material qualities from terribly brown to top-quality banded material.
Cutting quality:
The vast majority of “cabochons” on offer show low cutting quality. Very frequently cabochons are cut with rounded corners (similar to a palmstone) which do not show any bezel.
Quality Grading
Most cabochons were offered as AA or AAA quality, which obviously does not represent the reality. Given the fact that there is no commonly accepted grading standard AA and AAA gradings are used as a marketing strategy without reflecting a real criteria of quality. This type of marketing must be viewed as misleading.
Pricing
The average retail pricing for manganocalcite cabochons is 0.24 USD per carat (with a range from 0.03 USD per carat to 0.44 USD per carat).
We could not find a correlation between cutting quality or material quality and pricing. A higher price does not indicate a higher quality.
Jewelry Grade Material:
No impurities
Cutting Quality:
- Straight bezel (minor irregularities possible), 3 mm high
- Perfect dome (3-5 mm high)
- Edges between bezel and dome, as well as bezel and backside: sharp and crispy, minor chips on lower edge possible
- Backside flat at 280 grit, unpolished
Pricing:
Recommended Retail Price (A): 0.69 USD per carat
Jewelry Grade Material:
No impurities
Cutting Quality:
- Straight bezel, 3 mm high
- Flat and perfect dome (3 mm high)
- Edges between bezel and dome, as well as bezel and backside: sharp and crispy, minor chips on lower edge possible but very rare.
- Backside flat, at 280 grit
Additional Quality (AA+): Backside polished to 3000 grit
Pricing:
Recommended Retail Price (AA): 0.99 USD per carat
AA+: 1.09 USD/c
Jewelry Grade Material:
No impurities
Cutting Quality:
- Only cut by our best master cutters
- Straight bezel, 3 mm high
- Flat and perfect dome (1-3 mm high)
- The edges between the bezel and dome, as well as the bezel and backside, are sharp and crispy, with no chips on the lower edge.
Additional Quality (AAA+): Backside polished to 3000 grit
Pricing:
Recommended Retail Price (AAA): 1.29 USD per carat
AAA+: 1.39 USD
Is there anything you wish to know about:
Shipping cost and logistics, Payment options, Product quality, Packaging, Shipping damage, Refunds, etc. ?
Cutting services
Do you need reliable high-quality cutting services for a reasonable price? Are you looking for a service provider that is willing to develop new products according to your requirements? Would you like to get expert advice in order to improve your product? Do you wish for someone to optimize the process and get the most out of your rough? Just talk to us.
Get in Touch
+51 994104206
gemrockinternational@gmail.com