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DISCOVER

Precious Chroma offers a wide variety of carefully selected gemstones,
with a focus on original designs, under the theme of "something that may or may not exist anywhere else...".

In addition to the jewelry, the interior space of the store is also carefully designed.
For example, the showcases that decorate the store are made of acrylic, which expresses a sense of floating and design space that glass cannot produce.

Precious Chroma's store is also filled with other ideas and touches to maximize the beauty of gemstones and jewelry.

We look forward to welcoming you to our store, where you will find "unique jewelry".

Jewellery Column

Mining

In this glorious first installment of my jewelry column, I'm going to talk about gemstones, and when I say gemstones, I mean Mining..., probably.
Mining is, of course, blasting (gunpowder/explosives), isn't it?
There are two national qualifications for handling blasting: blasting engineer under the jurisdiction of the Ministry of Health, Labor and Welfare, and explosives handling (production and safety) supervisor under the jurisdiction of the Ministry of Economy, Trade and Industry.
The owner's love for the business led him to obtain a dangerous-sounding certification as a Class A Explosives Handling Safety Officer.
Mo mo mo mo mo...self-satisfied imagination...I'm just imagining that when I become a gemstone miner in the future, I will be able to dig for gemstones.
As a bonus, those with Class A certification were also able to obtain a concrete crusher operator (pyrotechnics) certification by attending a legal training session and taking a final examination (now discontinued).
Well, it is a qualification with a strong boyish element. It is like building plastic models of tanks and rockets! (laugh).

Quarrying/Crushed Stone

The fourth issue of this series focuses on quarry operations managers. This is a national certification required to manage the extraction of rocks crushed by mine blasting.
Without this qualification, the act is not even recognized as a job. This is because mining operations and quarrying are national lands and involve national interests.
This is the same principle that led the feudal lords of the Warring States and the Tokugawa Shogunate to place gold and silver mines under their direct control.
Gemstones are generally minerals, so they are subject to mining laws, while fossils and other rocks are subject to quarrying laws.
Although it is a national land, it is under the jurisdiction of the Energy Agency of the Ministry of Economy, Trade and Industry. This qualification is minor in spite of its broad scope of study.
The book covers not only geology/petrology, but also stone quarrying, surveying, environmental/pollution prevention, cultural asset protection, mine blasting, and heavy equipment construction/handling, making it a must for those who love it!

Transportration

The third in this series is cargo or trucks, i.e., working vehicles. They carry rocks that have been crushed by blasting to refineries. They are also called construction and heavy equipment.
Normally, we would like to cross and traverse the continent with large class 1 vehicles or special vehicles, but the trucks used in large gem mines are unmanned and run like radio-controlled vehicles!。
Mining is always risky. The cost of mining is naturally added to the cost of the gemstones. Mines of medium size or smaller are operated by manned trucks or human labor.
Therefore, natural gemstones are inherently more expensive due to the amount of time and effort spent on them.
Anyway, a nice national certification to have in such a case is an operation manager under the jurisdiction of the Ministry of Land, Infrastructure, Transport and Tourism.
The two categories are cargo for courier services and logistics, and passenger for buses, hired cars, and cabs. The owner of the store obtained the certificate in the cargo category.。
My backpacking career led me directly to start my own travel business.
I was also intensely curious about the qualification category "passenger. However, I decided to take a detour and a road trip on the actual trip.
It's fun to travel the world with intense fantasies, but you can't beat real life! It's also fun to use your credentials.

Others

This is the second installment of this series. This time, we will focus on the "crucible," or to put it simply, the high-pressure oven. It produces synthetic gemstones. It is used to power gem mining operations, to make semiconductor components, watch parts, and of course, some jewelry, as well as the bar code readers in cash registers. The equivalent of this national certification is that of a boiler technician.
Generally, boilers are associated with air conditioning systems for buildings, department stores, and condominiums, and power sources for factories, but they are also used to make synthetic gemstones as mentioned above.
Once again, the owner's hobby has taken off, and he even obtained a first-class boiler technician (he passed the exam).
I just genuinely wanted the knowledge that synthetic gemstones are made at high temperatures and pressures.
It is not that I wanted to make stewed pork cubes or small baskets (although I prefer these because they are tastier).
These boiler engineers are classified by grade. The lower level qualifications start with Level 2, which can be obtained by passing a written examination. From the first level, a diploma is awarded after passing the examination and after a certain period of practical experience in boiler operation is demonstrated. The highest qualification is Special Class Boiler Engineer.
If you are a knowledge-only gopher like the shopkeeper, the highest level is to pass the first level exam. As long as Japan does not collapse, passing the exam is still valid. However, it does not guarantee employment.

About

ABOUT OWNERTOKURA hiroyuki

After graduating from university with a major in history/archaeology, he studied the basics of jewellery making in Glasgow, Scotland, and the basics of diamond appraisal in Antwerp, Belgium, where he earned a diploma. After returning to Japan, he worked for a diamond import and wholesale trading company, where he was involved in jewellery sales planning mainly for department stores.
He then moved into the diamond appraisal institute and spent his days as an appraiser. Soon after, he worked in a gem mine in Belo Horizonte, Brazil. For his studies, he earned a diploma in gemmology in Idar-Oberstein, Germany, and studied antique jewelry in London, U.K.
To Brazil via London. He worked in a gemstone mine and was involved in the selection of gemstones with the determination to win a mine. After some twists and turns, he returned to Japan.
Thinking that what he lacked was something related to pearls, he jumped into the largest trading company in the pearl industry. A few years later, he decided to move to his hometown of Jiyugaoka,Tokyo and set up a jewellery shop there...
However, due to a sense of social stagnation, he recently began attending graduate school, completing a master's degree in museum studies and obtaining a curatorial appointment. While working as a commissioned curator at a certain university historical archive, he entered the doctoral course but withdrew after earning credits, up to present.

QUALIFICATION Tokura HiroyukiExplanation Of Gemmological Credentials

About Gemological Qualifications
♦ Member of Deutsche Gemmologische Gesellschaft(F.G.G.)
♦ HRD-Certified Diamond Grader (HRD-C.D.G.)
♦ International Gemological Institute Diamond Graduate, D.G. (IGI-D.G.)
♦ Gemological Institute Of America's Applied Jewelry Professional (GIA-A.J.P.)
♦ UNDERSTANDING JEWELLERY COURSE (Sotheby's Institute of Art)
♦ Platinum Guild International (PGI) Certified Platinum Expert
♦ Pearl Science Laboratory (PSL) Certified Pearl Grand Master

Member of Deutsche Gemmologische Gesellschaft(F.G.G.)

Deutsche Gemmologische Gesellschaft is located in the world-renowned gem city of Idar-Oberstein and is constantly acquiring and disseminating the latest information on gemstones.
In order to obtain a certificate of membership of Deutsche Gemmologische Gesellschaft, a student must take a class in appraisal/identification involving a certain number of diamonds, colored stones, pearls, and other organic materials, and then pass a practical examination, a paper test, and an oral examination.
In addition, to remain a member after graduation, you must take a training course of less than a week every five years and pass a confirmation test to renew your membership!
While many associations and societies in various countries only allow their members to obtain certification once and be done with it, this is the only certification renewal system in the world. It is a system that is typical of the diligent German Meisters.
Official Site>>　Deutsche Gemmologische Gesellschaft

HRD-Certified Diamond Grader（HRD-C.D.G.）

HRD is the official representative body of the Belgian diamond industry. It is a non-profit organization called the Diamond High Council (HRD). The standard here is the International Diamond Council's grading system (IDC).
The IDC Regulations were officially adopted by the world's two diamond trade associations, the World Federation of the Diamond Trade (WFDB) and the International Diamond Manufacturers Association (IDMA).
In addition, HRD Labs is currently the only appraisal organization in the world with official ISO accreditation. As such, it must undergo extensive and rigorous inspections on a regular basis, and from a structural, organizational, and technical standpoint, its quality control is among the most stringent in the world for appraiser certification.
Official Site>>　HRD

International Gemological Institute Diamond Graduate, D.G. （IGI-D.G.）

International Gemmological Institute is one of the largest independent international gemological and identification organizations serving all aspects of the diamond, colored stone and gemstone industries.。
The oldest institution of its kind in Antwerp, I.G.I. was founded in 1975 and, together with its sister institute in New York, is the leading gemological institute in the world.
Starting with a staff of three, today it has more than 250 professionals and is recognized for a level of excellence second to none in Antwerp, New York, Bangkok, Mumbai and Tokyo, producing more than 400,000 reports a year.
Official Site>>　International Gemmological Institute

Bangkok - GIA.edu

GIA, founded in 1931 in Southern California, is the largest network of non-profit gemological institutions in the world.
Official Site>>　Bangkok - GIA.edu

UNDERSTANDING JEWELLERY COURSE(Sotheby's Institute of Art)

The course was originally based on the book UNDERSTANDING JEWELLERY. Currently, this course is no longer offered.
Official Site>>　Sotheby’s Institute of Art

Platinum Guild International (PGI) Certified Platinum Expert

Access

  • ＃101, Jiyugaoka Flat, 1-24-6, Jiyugaoka, Meguro-ku, TOKYO
  • Opening Hours
    Monday - Sunday　　　　11.00 - 19.00

    Open irregular holidays; please make a reservation when visiting.
  • * May be closed due to the owner's condition. Please inquire in advance.

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